I receive so many requests for information and help from visitors to this site that I have decided to set up this help and information blog. I will start posting information about these bikes, their maintenance, common problems and factory specs as I find time to do so. SAFETY MUST PRECEED BEAUTY so there will be no information about cosmetics. Everyone’s idea of a “nice” bike is their own. If you’re reading this you have likely come into possession of an XS1100 recently. That being the case I will start with what I will call the “new to you XS1100”. It is what you should do as a minimum when you receive the bike from an unknown source. It is a list of what I would do in any case.


Get a MANUAL for this bike.  You’re going to need it sooner or later and all too often, later will be too late and serious damage will have been done.  You can still get new after market manuals from many sources or buy one used on e-Bay. Factory manuals are available from time to time on e-bay and a CD version is also obtainable.

The first thing to do while you wait for your manual to arrive is give the bike a good cleaning. It’s a lot easier to trouble shoot and work on a bike that is clean. Cleaning should include an engine degreasing followed by a good wash and rinse. While washing the bike try to avoid spraying water into places it would not normally get to in normal use. If the recommended degreasing is carried out do not panic when you see smoke coming off hot engine surfaces when the engine is run for the first time after the degreasing.

The first thing to do is a safety check followed by safety related repairs or maintenance to make the bike safe to use.

1-       Check the condition of the tires. Even if the tread looks good and is not worn to the wear bars that can be seen between the treads, the rubber may be hard, cracked or permanently distorted by improper storage.  Most motorcycle tire manufacturers recommend that tires be changed every 4 years no mater what they look like. Getting the wheels balanced is also in order even if the tires that came on the bike are going to be used.

2-       Check the brakes for proper operation, shoe wear and adjustment at the front and rear of the bike. See, you need your manual already. The brakes should operate smoothly and the brake shoes must fully release when pressure is removed from the front brake lever or the rear brake peddle. If ether the front or back brake systems are difficult to operate or the shoes do not fully release, a full brake rebuild is in order for the system that is faulty.  If the brakes are working properly (be fussy about this conclusion) all that needs to be done is to replace the brake fluid in both systems. In the front, bleed the calliper that is the farthest from the master cylinder first. USE ONLY DOT 3 fluid.  Just bleed the new fluid through the system until you see the new fluid coming out at the calliper bleeding nipples. Do one caliper at at time and don’t let the master cylinder go too low of brake fluid while doing this operation or air will enter the system and you will have a different job on your hands to get it out. Check the thickness of the brake shoes. There’s a viewing door on the top of each calliper for this purpose. There are wear indication lines on the tops of the shoes. If the shoes are worn to those indication lines, replace the shoes. If your replacing the shoes do them is sets. In other words all the fronts or both shoes at the rear. Do not replace the shoes on only one calliper of the front brakes. The bike will pull to that side during quick stops making the bike somewhat dangerous to use.  Also note that the manufacturer clearly states that the brake hoses are to be replaced every 4 years. Given that the bike is rather old the brake hoses are likely toast no matter what they look like. They fall apart from the inside out.  If hose replacement is on your list. Replace with stainless steel braided hoses. New Old Stock hoses are difficult to find and if you do find them they will cost about the same as SS hoses. SS hoses will provide GREAT braking power for this fast heavy bike.

3-       Check the suspension systems for proper operation. With the front brake on you should be able to depress the front forks several time with the weight of the bike. The up and down operation of the forks should be smooth with no binding in their travel. The forks should also rebound to the normal static position each time. Unless the bike has been dropped or involved in an accident the forks will likely work as they are suppose to. The upper fork tubes must be free of rust, pitting or other damage through their entire sliding range. If not the upper fork tubes will need to be replaced.  If the front forks are working properly your only job will be to change out the fork fluid. Do only one leg at a time or the bike WILL fall forward as soon as you remove the fork cap on the second leg. The rear shocks require no maintenance and are not repairable. The rear shocks should support you weight and any intended load without bottoming out. They should rebound to their full static position as soon as you get off the bike. If not, replace them outright.

4-       Check the Steering system for proper operation. Make sure the handlebars move smoothly and freely from the full left steering stop to the full right steering stop without binding and without the handlebars contacting the fuel tank. The adjustment of the head set bearing should also be checked as part of the steering system. With the bike on the main stand and the front wheel off the ground there should be no free play in the head set bearing when you push / pull on the forks.

      5-   Check the throttle and clutch cables for proper operation. The throttle cable should work smoothly through its full twistable range and return to full stop when the grip is released. It should spring back to the stop position quickly and smoothly. It should literally snap back to the stop position. Any binding must be corrected. Binding can be the result of improper cable routing or the cable may just need to be lubricated.  The clutch cable should allow for smooth operation of the clutch lever through the levers full range of movement.  When the clutch lever is released it should return to its original position. Both these cables should be lubricated as per the manual.

6-       Check the frame for any cracked or broken joints at all the wield points and check the lower frame tubes under the engine for rust through. This tends to happen on the side stand side of the bike if the frame drain holes have become plugged and water got trapped

7-      Check the lighting systems and horn for proper operation. Lighting system includes the headlight (both high and low beams), tail light, turn signal lights, front running lights, instrument pod lights and gage lights. All these systems should work with the main switch keyed to the on position with the exception of the head light. The engine must be running for the headlight to be tested. On the 78 and 79 model the front turn signal lights double as front running lights so they should be on with the main switch keyed to the on position. The horn should also operate with the main switch keyed to the on position. 

8-      Check the foot peg rubber and peg spring action for proper operation. The rider pegs should move upward when pushed up and spring back to their static position when upward pressure is removed. The passenger pegs are not spring loaded but should flip up and stay up when they are not in use. The rubber covering on both the front and rear pets should have enough tread on them to give the rider or passenger a good foot hold on the pegs. Replace the rubber covers if they are worn out.

9-      Beyond what is listed here the bike MUST of course pass a state or provincial safety check before it should be considered to be road worthy.

The next thing to do is replace the engine and drive system oils and carry out a fitness check 

1-    Change the engine oil along with the engine oil filter. You will have to change it out cold unless you have a running engine. If you do, then drain the oil once the engine has been warmed up. The oil pan drain plug is on the front left side of the oil pan which is the pan on the bottom of the engine. Remove this plug to drain the engine oil. If you have a fine screen of some sort you can drain the oil through it so you can check for metal filings which might indicate an impending engine issue. The oil filter is in the engine filter bowl which is the circular bowl on the bottom front of the engine. For both these tasks use care to not strip the drain plug or filter bowl bolt threads. Let the engine drain for about 20 minutes. Wait longer if draining the oil cold. After the engine oil is fully drained and the new oil filter is installed in the filter bowl, fill the filter bowl with new oil and apply a little bit of anti-seize grease to the threads of the filter bowl bolt and the drain plug. This will make future removal much easier. 

 Install the plug and the filter bowl with new filter as instructed in the manual and torque them to the correct value stated in the manual. The engine oil filler cap is located on the engine clutch cover on the top and towards the back of that cover. The clutch cover is the largest engine cover on the right hand side of the engine. Refer to your manual and fill the engine with the correct weight, type and amount of engine oil for your current temperature range. DO NOT OVER FILL and DO NOT USE synthetic oil. This engine uses a “wet” clutch that shares its oil needs with the engine from the same oil pan. The transmission also uses the same oil supply.

2-   Change the middle gear oil. The middle gear is the unit that is attached to the engine’s left hand side toward the rear of the engine. It has a Circular chrome cover on it. The drain plug for the middle gear is on the bottom of the middle gear case. It is up in a recess so you can’t readily see it by just looking under the middle gear housing. This drain bolt can sometime be tight but it’s a good sized bolt and can be removed with the right sized socket and ½ inch drive ratchet. The filler cover bolt is on top of the middle gear. It is a socket head bolt that may still have a small black plastic plug on the bolt to keep the HEX socket opening clear of debris. THIS BOLT WILL BE VERY TIGHT and often needs to be approached with a bit of additional leverage. First make sure you have the EXACT size HEX wrench or HEX socket and that it fits fully into the HEX opening on the top of the filler bolt. Most HEX wrenches are too short and too small to get the leverage required to loosen this filler bolt so use a ½ inch drive ratchet and HEX socket if at all possible. If you must use a standard type HEX wrench slip the piece of pipe over the wrench or clamp the wrench into the jaws of a vice grip pliers to make the handle longer and easier to grip.  The middle gear oil is heavy so the middle gear should be let to drain for an hour unless it’s being drained hot. Even hot, 20 minutes is the norm to drain the middle gear.  Apply a little bit of anti-seize grease to the threads of the drain bolt and filler cap bolt during reassembly so removal in the future will be easier. DO NOT FILL THE MIDDLE GEAR WITH ENGINE OIL. The middle gear uses special hypoid gear oil. Check your manual for the proper weight, type and amount of oil to use. Install the drain plug and torque as per the manual. Fill the middle gear with the right amount of the right weight and type of oil. Install the filler cap bolt and torque as per the manual.

 3-     Change the final drive gear oil. The final drive unit is at the center of the rear wheel on the left side of the bike. The drain plug is on the bottom center of the unit .This drain bolt can sometime be tight but it’s a good sized bolt and can be removed with the right sized socket and ½ inch drive ratchet. The filler cap bolt IS NOT ON TOP OF THE UNIT. The cap on the top of the final drive unit is the vent. DO NOT TRY TO REMOVE IT.  The filler cap bolt in at the 3 PM position when you’re looking at the final drive unit. It is a socket head bolt that may still have a small black plastic plug on the bolt to keep the HEX socket opening clear of debris. THIS BOLT WILL BE VERY TIGHT and often needs to be approached with a bit of additional leverage. First make sure you have the EXACT size HEX wrench or HEX socket and that it fits fully into the HEX opening on the top of the filler bolt. Most HEX wrenches are too short and too small to get the leverage required to loosen this filler bolt so use a ½ inch drive ratchet and HEX socket if at all possible. If you must use a standard type HEX wrench slip the piece of pipe over the wrench or clamp the wrench into the jaws of a vice grip pliers to make the handle longer and easier to grip. The Final gear oil is heavy so the Final gear should be let to drain for an hour unless it’s being drained hot. Even hot, 20 minutes is the norm to drain the Final gear.  Apply a little bit of anti-seize grease to the threads of the drain bolt and filler cap bolt during reassembly so removal in the future will be easier. DO NOT FILL THE FINAL DRIVE GEAR WITH ENGINE OIL. The final gear uses special hypoid gear oil. Check your manual for the proper weight, type and amount of oil to use. Install the drain plug and torque as per the manual. Fill the final drive with the right amount of the right weight and type of oil. Install the filler cap bolt and torque as per the manual.

 4-   Grease the Final drive gears. There is a nipple for this on the final drive shaft but most will not count on this to get the grease to where it needs to go. To properly grease the final drive gears you should remove the final drive unit and grease the gears by hand. This is not a difficult job to do and should be considered as part of the mechanical check up.

 5-   Check the swing arm bearings. While the rear wheel off for balancing or to address the final gear re-greasing job, check the swing arm bearings for free play. To do this you will also need to remove the rear shocks. With the rear shocks removed the swing arm should move up and down only and should do so smoothly and without binding through its full range of movement. You should not be able to rock the swing arm sideways or move it forward or pull it backwards. Attempting to twist the swing arm should reveal no free play. The swing arm should also not move side to side on the bearing pins. If there is free play the bearings should be inspected / re-greased and or replaced outright. NOTE: If you find yourself removing the swing arm for inspection or replacement of the bearings the torque for the swing arm bearing pins IS NOT 40 FOOT POUNDS as many manuals state. It is 4 foot pounds. The swing arm bearings are tapered bearings that do not take very much torque. Some say hand firm only for this type of bearing. The pin lock nuts can be tightened as per the manual s torque spec. Another tip to do here while the rear axle as been removed is to apply a thin coating of wheel bearing grease to the entire axle. This will keep the rear axle from bonding into the very rare discontinued  left side wheel bearing made only for Yamaha that is part of the rear wheels setup. On bikes that have not been maintained properly and not had the rear axle removed in many years, the axle can become bonded into this bearing and often only be removed by destroying that bearing.  

 6-   Check the air delivery system. The air intake system consists of the air box and its air filter along with the often overlooked venting hoses for the engine and carbs. The air box and filter are pretty straight forward. The bottom of the air box is removed by loosening the 4 wing nut type bolts on the bottom of the air box. There is one wing nut towards each corner of the bottom half of the air box. When loosened completely the bottom of the air box will drop down onto the engine for removal on the left side of the bike. The filter will be sitting on the bottom half that your removing. It should be cleaned with compressed air if it’s the stock paper type or cleaned with a mild solvent if it’s the oiled type that many owners use on these bikes. If it the oiled type it will need to be re-oiled after it is cleaned. Special oil is needed for this filter so off to the bike shop you go. The vents at the top front of the air box also MUST to be checked to confirm that they are not blocked. This will include the nipples that are part of the air box as well as the hoses that attach to these nipples. If these vent passage ways are blocked the bike will not run because the carbs will not work properly and engine flooding will be a chronic problem. It is easier to check these nipples when the carbs are removed which is the next job on the list which will be fuel delivery systems.

 7-   Check the fuel delivery systems. This check starts with the fuel tank and fuel petcocks. The fuel tanks on these old bikes are often very rusty and will need to be cleaned and or relined. To clean the fuel tank you will need to remove it, drain it and let it air dry somewhere safe. Once that is done remove the fuel petcocks and put them aside. Apply heavy duct tape over the holes for the fuel petcocks. Add a roll (50) of loose pennies to the fuel tank along with about ½ cup of light oil like WD40 or air tool oil. Close the fuel filler door and shake the fuel tank in a fashion that the pennies are slid around on the inside surface of the fuel tank. The intention is not to have the pennies bouncing around in the tank but rather sliding around on its inside surfaces to remove loose rust. You will need to allow the pennies to slide over all the inside surfaces so the tanks position will have to be changed accordingly throughout the process. It is impossible to tell how long this will take because no 2 tanks will be in the same condition. However about 15 minutes per surface should do a pretty good job. Once this is complete you will need to recover the pennies and flush the tank with more light oil followed by a rinse with gas. If the fuel tank is in very poor condition you might have to have it lined or replace it.  

 Now it’s time to check the fuel petcocks for smooth and proper operation. Many will just replace them with aftermarket units that are a simple on / off design but that’s up to you. Given that the bike is 30 so odd years old you will most likely need to rebuild the fuel petcocks but that job will not be covered here in detail. The rebuild kits are available and rebuilding is easy enough but GREAT CARE MUST BE EXERCISED to make sure they are reassembled properly. There are no instructions on petcock rebuilding in the manual and the provided pictures are crude so you will have to make notes and or take photos during the disassembly of the units. Once they are apart clean them very carefully with carb cleaner and SOFT brushes. Make sure all channels are clear of fuel deposits and fuel gum. They must be perfectly clean if they are going to work as intended. If you take your time and allow the parts to soak long enough in a good quality carb cleaner you should be ok. The screens also need to be cleaned and it’s best to do that with compressed air. The screens are fragile when old so handle them with care. Once the fuel petcocks have been cleaned and rebuilt reinstall them on the fuel tank in their correct positions (they are marked on the bodies as being left or right) and bench test them.  Fuel should flow freely when the levers are in the “prime” position and no fuel should flow when the levers are in the “on” or “reserve” positions. Note that the lever should be treated like the hands on a clock when selecting its position. The lever will be over the chosen selection. If this test works the next test is to confirm that fuel will flow in both the “on” and “reserve” positions when a vacuum is applied to the smaller nipple of the fuel petcock. This can be done with hand vacuum pump with a SMALL amount of vacuum applied or with a long air hose and just suck on it but not so as to draw gas into your mouth if the petcock is not working correctly. It does not take very much vacuum to make the fuel flow if the petcock is working properly.  If the fuel petcocks fail these tests rebuild them again or replace them with simple on / off units that can be obtained. The fuel petcocks MUST work as intended or you will have chronic engine flooding problems, Gas in your engine oil and other serious problems.

The next part of the fuel delivery system is the fuel and vacuum supply hoses, all of them. Check them to confirm that they are still soft, flexible and not blocked. It is most likely that this will not be the case and you will likely need to replace all the hoses. They can be obtained at small engine shops, bike dealers and a few places on line like e-bay. Make sure to replace them with the “thin wall” type fuel hoses as room between the carbs is tight even with the “thin wall” type. 

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  1. chris says:

    the cam chain tensioner bolt backed out of its housing and I am having a hell of a time trying to find a replacement for it.any suggestions would be a great help.

    • Hi
      The cam chain tensioner bolts that hold the entire unit to the front of the engine as well as the holding bolt and the lock nut that go into the side of the tensioner can be found at Yamaha dealers or for that matter they can be matched up at hardware specialty shops that carry metric hardware. There’s really nothing special about any of those bolts and lock nut. They are pretty common. Go stainless steel while your at it.
      On a different note many owners have completely changed out the cam chain tensioner unit to the type that are used on the later Venture models. The units from the venture model are self adjusting and require no maintenance once they are installed. They bolt right on but of course care muct be taken to make sure that the timing is not changed while doing the switch out. Check out and search for Venture cam chain tensioner for addition details about which units fit by model year and making the change. The units themselves can be found on ebay pretty cheap.
      Hope that helps.

  2. Jim Boudrot says:

    hey man. I just got my 79 xs1100 running, but I can’t engage the throttle. The throttle cable is hooked up to the #2 carburetor but the throttle grip is just loose and does not retract at all when I turn it back. So the bike starts up just fine but I can’t give it any gas with the throttle. If you have any suggestions I would greatly appreciate it.

    • The throttle grip does not have any springs or other recoil devices inside it. The throttle action is controlled by the butterfly springs that are right on the carbs. So from what your telling me I would suggest that you open up the throttle grip by removing the handle bar control that is also the throttle grip housing and make sure the cable is properly engaged with in the grip. The cable should come up through the hole in the bottom of the control box where the steel curved part goes and then over the guide wheel front to back and into the slot that holds it in place. You can see how it goes together by visiting Yamaha’s web page and looking into their parts catalog where they have exploded views of all systems. If the cable is properly set up in the grip and the cable is not pinched along its route to the carbs and the carb return springs are working properly, then perhaps the cable is too long as can happen if the cable is designed for the “special” models that had the taller handlebars.
      Hope that helps

  3. pat whalen says:

    I have a 1978 xs1100.and it’s only running on two cyclinders 3&4, it’s got spark .could it be the carbs ?not getting gas. thanks

    • That’s very unusual because the carbs are paired 1&2 + 3&4 so fuel supply issues typically show up paired the same way. Ignition is paired 1&4 + 2&3 so typically ignition issues appear paired that way. This being the case and with spark confirmed across the board, check the carbs on 2&3 but do note that it is not uncommon for a plug that will spark out of the cylinder to fail once it is subjected to the pressure inside the cylinder. If it were my engine I would check compression across the board, Check and confirm the timing including the valve timing, Test and confirm the coils, leads and plug caps and of course … clean and set up the carbs.

  4. dave says:

    ok so i have a 1979 yamaha xs 1100 just bought it and it’s very clean.. but when started the right side of the fuel filer is completely full and the left is half full …should i be concerned? and it back fires when started sometimes but not after it’s warm..thank you

    • Fuel lines and filters should be full. See if the filter will fill in the “prime” position. Check that fuel petcock screens in the fuel tank are not pluged. Will they fill in the “prime” position?
      If it is only back firing at start up I would start by telling you to confirm that the carbs are not flooding into the cylinders. In other words, she may be running rich at start up to burn off that added fuel. Check your oil for fuel. Take a sniff of the fumes from the oil fill hole at the top of the clutch casing. check the oil level. Is it increasing? Use a dip stick and get some oil on it. If it is easy to light with a match / lighter, you have gas in the oil which happens when fuel is getting past the carb needle valves and flowing into the cylinders when the bike is parked. Carbs on these bikes MUST be clean like new for the engine ot run well.
      Hope that helps

  5. Don Phillips says:

    Not getting any vacuum at No.4 carb manafold with vacuum gauge, have 138 psi compression on No.4 cylinder

    • If your using a gang of 4 vac gages on a rack make sure the control valve in not stuck in the closed position. If your sure your gage is working properly then it is likely a case of the vac tube that goes into the carb intake boot being pluged. If plugged, try not to dislodge what ever is blocking it into the intake manifold. If by chance the gage and the vac manifold tube are not the issue, then you may have an intake valve that is not opening but that would really be a stretch.
      Hope that’s helpful

      • Don Phillips says:

        Rob thanks, one more question for you, which is the better gang vac. gauge, the vert. tube type or the dial type gauge, I have the old mecury tube type, have been looking at the dial gauges, would like some input before shelling out $120 bucks.
        Thanks again Rob

      • If your comfortable with your mercury tubes they do work well enough. It’s not about the numbers it about all the numbers being the same. Myself I like the gages because I can hook them up in about 3 minutes with no worries about spilling the mercury, breaking the tubes etc. The gage set I use were in around what your quoting on price. I got them on Ebay and they work well. The bike runs at her best when the carbs are in perfect balance. If you do get a gang of 4, which I think is the best bet compared to moving one gage from cylinder to cylinder, you can confirm that they are all reading the same by hooking each one up to the same cylinder one at a time. They should all read the same value on that cylinder. If not, some can have the neddle’s position “corrected” by way of a small set screw on the back of the gage. These ones will however cost more. When adjusting the carbs make VERY small adjustments at a time and give the throttle a quick but short twist so the butterflys can return to their fully static position before checing the effect of the adjustment. do 1 and 2 to each other, 3 and 4 to each other and then the two pairs to each other. Did you find out what was up with the lack of vaccum on that #4 cylinder?

      • Don Phillips says:

        Thanks for the reply, the low vacum on nu.4 was due to the adj. screw between 3&4 carb. it was flooding nu.4 cyl. dont know how it got screwed down so far. Pulled the carbs cleaned all the float boxes and reset all the adj. screws to where they were barely touching the pads and got vacuum back on #4, was relieved that the smoke from #4 stopped thought sure I had a bad valve guide leak.
        As far as the gauges, think im going to the dial type, dont like the condensation in the mecury tubes, seems to have some kind of reaction in the plastic, causes the plastic to crack.
        Thanks for the info Rob
        PS. do you have a brand of gauges you would recommend

  6. The ones I have a generic with no name on them so their likey made in China but they work well. Here’s a few examples. If you want high brand name quality go with S&W, Inficon, Hyvac. There’s lots of manufaxcturers out there and you can always buy indivigual gages and mount them on a rack yourself but If you do that you will not get all the accessories which are handy.

    This is what I have but I see that the price has moved upward.

    Similar to what I have but is used. Sharp price

    another type

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  9. Brian Pacer says:

    I have a 79 xs1100.. would like to know what oils to use in the bike and how much. For the block. Middle and finale on the back tire….thanks brian

    • Hi Brian, As per the FACTORY Manual:
      The engine capacity is 4.3 US quarts from DRY, Oil change is 3.2 US quarts, Oil and filter change is 3.7 US quarts.
      Recommended lubricant type is:
      SAE 20W/40 SE motor oil if temperatures does not go below 40* F.
      SAE 10W/30 SE motor oil if temperature does not go above 60* F.
      Note, use only NON synthetic oil in this engine.
      Middle gear case capacity is .38 US quarts.
      Recommended lubricant is:
      SAE 90 Hypoid gear oil GL-4 if temperatures does not drop below 40* F.
      SAE 80 Hypoid gear oil GL-4 if temperature does not go above 60* F.
      All Weather 80W/90 Hypoid gear oil GL-4
      Final drive case capacity is .32 US Quarts
      Recommended lubricant is:
      SAE 90 Hypoid gear oil GL-4 if temperatures does not drop below 40* F.
      SAE 80 Hypoid gear oil GL-4 if temperature does not go above 60* F.
      All Weather 80W/90 Hypoid gear oil GL-4

      Always use the dip stick to confirm middle and final gear oil levels and the sight glass at the bottom of the clutch cover to confirm engine oil level.

  10. grant russ says:

    I have oil running in to the manifold pipes. need ideas of what to do first. 1981 1100 special.

    • Oil in the exhaust header pipes can be caused by a few things like: worn rings allowing too much oil blow by on the down stroke of the piston, Worn valve guides and or worn out valve guide seals, using an oil that is too light. What other symptoms, if any, are present? Is this a new development?

      • grant russ says:

        This is a new problem. I had just changed the oil and have only run it maybe one hour. With the oil drip off the bottom which I can’t find the point of the leak and smoke off the pipes I have not run it very long. I don’t want the pipe temp to start a fire.

      • Did you also do a filter change. Often times oil will end up on the top side of the header pipes when the oil filter is also changed. If oil filter was also changed check that the O-ring is not leaking. It can get miss-located during the installation of the filter. That chamber is under pressure so oil can spray out past a damaged O-ring when the engine is running.

  11. James says:

    So I have an xs1100 that I picked up just a while ago. I’ve been working on restoring it and getting it running again. I had a question regarding one of the vent tubes that comes off the crankcase. I know about the main breather tube that connects to the air box and I have it hooked up right. My question is regarding another slender tube that comes off a dome like piece and it is right next to the main crank case breather tube. I am not sure about hooking it up or what it does and I want to be sure I have everything hooked up right before running it. Can someone tell me what this other small tube is for, where it goes, etc?

    • That small diameter tube is simply a vent. It does not hook up to anything. On my bikes I run over the back end of the crank case and through the double tube guide on the lower rear frame cross member. the same one that the battery vent goes through. However, some people prefer to run it up the side of the frame that has it end at a point near the battery. The routing of that tube is not covered even in the factory manual but I believe that if it was to run up the side of the frame, the hose nipple would be facing sideways as compared to straight back.

      • James says:

        Hi, I wanted to ask if you have ever had issues with the throttle cable slipping down where ot connects to the carb. My xs11 has lower handle bars on it so it seems like the cable now is a little too long. I wanted to check before getting a new one if you have ever worked with this or found a way to better secure the cable down by the tab where it connects to the carb.

      • I have not in the past ever had the throttle cable become dislodged from it’s guide on top of the carbs. It is held in position by the spring pressure that is created at the carbs return spring. Make sure that you have the right cable and that it has been routed in the frame as per the manual. The specials used longer cables which creates an unacceptably large loop up front of the standard models when routed so as to not kink but even that would not make it want to jump out of the keeper. The cable you have may not be an original so the end may not be a proper fit at the carb. It may be from a different Yamaha model or routed incorrectly. It may be binding in the covering enough to over ride the return spring at the carb. Also check at the carbs to make sure that the cable guide on the middle carb top bridge is in the correct location. It should be at the front of the carbs. Remove the cable and measure its length and compare that to the specs that are often posted at sites that sell cables. If your going with lower bars than stock, you should still be OK but could buy a shorter cable.

  12. James says:

    Yea that helped a lot, I had been going through the manual time and time again and could not find anything on that little breather tube. Thanks a lot for the help and the useful info that you have posted on your site. The xs1100 is new to me so I needed to know about all the special things that need to be done. I got it running the other day for the first time and it runs good on choke but dies out when I push the choke in. I’m taking the carbs apart again to make sure they are cleaned out really well and the pilot jet is all clear. Thanks!

  13. James says:

    So I’ve been riding my XS around and enjoying it a lot. I have changed all the oils and filters but I’m noticing a drip that seems to be coming when the bike is running and also when it is parked. The weird thing is it appears to be dripping from the bearing support cover on the left hand side above the advance cover where the shifter is. Any ideas on fixing this or what is causing it? I have been looking for some gaskets on line but have not found any relating to the bearing support cover. I do know that is is coming from that cover as the initial drip is forming right on the low point of that cover.

    • I’m not sure where your oil drip is but if you mean from the polished oblong cover above the shift lever cover your describing the starter motor cover and trany bearing support. The upper half of that cover is where the starter is mounted and the bottom is a bearing support for the tarny. Start by making sure the oil is not over filled. Do this on main stand on level ground and check it in the view glass on the bottom of the clutch cover. If over filled oil will be splashed up too high, become aerated and other damage can occur. If not over filled, pull the starter and check for signs of oil from the starter seal, the pressure sensor that is right behind the cylinders because oil from that location can be blown back and under the starter cover. If everything up top in the starter cavity is dry then your going to have to check the bearing seal that is part of the lower part of that cover. There are no gaskets under those covers. The bearing seal is an O ring between the cases but I have never seen one leak on any of my bikes. If all else fails Clean the engine in the are od concern really well. Start the bike and as soon as you see the first drop of oil forming at the drip location shut it down and repeat above to find this leak.

  14. ohughen says:

    Do you have any knowledge about if KN puts out any air filters that will fit 2 by 2 on an 81 xs? I was wanting to remove the stock air filter to make things easier to get to but did not really wish to go with 4 individual filters. Otis

    • Not right off hand but I do know that some people do have that sort of set up on their bikes. I just don’t know if it K&N or other. In any case 2 by 2 or individual the tuning issues will be the same. That being the case, I would go with individuals and good luck with the tuning.

  15. James says:

    So I was wondering about a carb problem. Are the needles in your float bowls rubber tipped or metal? Mine are just metal and it seems like I am still having problems with a very slight gas overflow where if the bike sits for a day or so some gas will start to over flow up into the intake chamber. I’m not sure if this could be solved by replacing the needles with rubber tipped ones so that it creates a better seal but I wanted to see if you had any of these problems before or knew of any solutions off hand.

    • The earlier XS11s use metal to metal needle valves but some later models made use of the rubber tipped ones. They are not the same so if you do opt to change out to factory or after market needle valves with the rubber tips, you will have to set the float height on the bench manually. It takes some time to do but can be done. You will have to buy the valves and the seats as a set for each carb. I have used both and did not find the rubber tipped ones to be any better or worse then the stock units. If you opt to go with the metal to metal arrangement check the tips of the valves and the condition of the valve seats closely wit ha magnifying glass. They must be PERFECT or they will leak. I always test them with a vac pump on the fuel line to confirm that there are no air leaks between the top of the fuel line and the needle valve. If the valves are PERFECT but you still have a flooding issue check to make sure that all of the air passages between the carbs and the air box are clear. If they become blocked or restricted the carb bowls will flood no matter how PERFECT the valves are.

      • James says:

        Thanks for the information, its been a gret help in getting my bike up and running. I have been trying to figure out what might be causing my bike to be a little slugish when I take off in first gear. I remeber reading your blog and seeing something about one of your bikes also being slow at the start or maybe I’m mistaken. Once i get going and Im in second it seems like it takes off pretty well. Any ideas on what might be causing that initial slow take off?

      • Im going to need some more info to come up with my opinion as to what the problem might be. So I need to know if the carb jetting is stock? Is the air bix still in place of has it been changed out for POD filters on each carb? Is the clutch in good shape. A slippery clutch can feel like a slugish engine when the spilage is consistent. send me that info and I’ll take a stab at the issue your having.

      • James says:

        Hi, yes the carb jets are stock. I have cleaned them well and the engine idles great. The air box is also stock, I just changed out the air filter for a new one when I bought the bike. The clutch seems like it had been working great but just the other day when I got on the bike I noticed that when I held in the clutch and shifted from neutral to 1st the transmission jumped and the bike stalled. I actually had to tighten the clutch screw to get it to stay in neutral when I shifted from neutral to first. Since then it seems like the bike does that just when I start it. Once i get it warmed up and going I dont have that problem when shifting from1st to neutral. I was also checking the diaphrams in the cadbs the other day and on one of them the seal was not solid maybe that is part of the problem. Let me know if you have any thoughts. Thanks

      • Start by setting up the clutch’s internal and external adjustments. Check your manual for the process. A slippery clutch can in deed feel like a sluggish engine start off. If not set up correctly It would also burn out the clutch sooner then if it is set up as per the manual.
        If adjusting the clutch does not make the issue go away then look at the idle screw settings, look for vacuum leaks (use quick start sprayed around the carbs with the engine running. And increase in idle speed when sprayed with quick start = a vacuum leak). If all that fails, check float height on the bench.

      • James says:

        So I have a new XS 1100 and I’m trying to split the crankcase I don’t know if you have ever done one before but do you have any advice on anything in the manual that isn’t covered. It seems like the case won’t budge at all and I have followed the manual precisely with removing all the bolts and pieces of the engine. I have even cut away the gasket with a razor how long were the two halves meet.

      • I have taken several apart over the years and the cases should “pop” right apart with a firm hit from a RUBBER mallet. I have however, only ever had to resort to that once. DOUBLE check that you have in deed removed EVERY case bolt. There are some that are somewhat hidden away and easily overlooked. Do you have the oil pan off?

      • You also have some parts that bridge the cases under the side covers eh? Like the oil supply casting that’s under the trany cover.

      • James says:

        Yea I have taken every bolt and the oil supply cover off too. I have the oil pan off and the and got the bolts under the oil screen area too. Its still not coming. Do you need to take the clutch and alternator assemblies completely off? I have the covers off right now but have not completely removed all components. I also have not taken off the cylinder head.

      • No the alternator rotor, clutch and cylinders do not “have” to be removed but in my own experience you will have difficulty on re-assembly with the alternator and clutch in place. The crank shaft oil seals have lips on them that are rather difficult to line up when putting the cases back together. It’s also a tight fit and you want the cases to go back together in one smooth operation. If I was doing it I would pull the clutch assembly and alternator rotor for ease of re-assembly. That alternator rotor will however, prove to be difficult to remove when the shaft is not secured in the cases. Been there done that so to speak. If you have removed all the bolts, and the oil delivery casting that bridges the cases, they should come apart without too much difficulty. Tap the perimeter with a rubber mallet while applying upward lift (2 person job). The bottom case MUST be lifted STRAIGHT off the top case due to the locating dowels between the cases. There can be no tilting during the lift off. Double check you process in your manual and do not skip any steps. Good luck with it.

      • James says:

        So I finally got the crank case separated by removing the three bolts that connect the drive shaft housing to the crank case. The alternator is still providing difficulty in getting the halves completely apart as you said it would. I was able to use a strap wrench to remove the bolt but the rotor is still not coming off. I wanted to ask you if you have removed one without the use of a fly wheel puller as I do not have one.

      • I have removed that rotor with a three leg puller and LOTS of HEAT applied to the rotor but not the shaft while torqueing the puller. When I pulled it off it “POPPED” off so don’t be standing in front of it and put something on the floor to break its fall so it does not get damaged hitting the floor. Check and mark its position on the shaft. Scratch a line because that rotor is balanced but I don’t know if it is balanced on the shaft or off the shaft. I applied a lot of force to the puller and then added heat, tightened the puller bolt more and added more heat. I did this several times until it jumped off the shaft. Be careful and good luck with it.

  16. Raymond Sostarich says:

    Hello. I have a 1979 XS e model, and I had just gotten in ukp-it has been almost a year for this project. I am greatfull for this site, as I have learned so much. I posted a question about electrical problems here befor. My bike had been taken care of until someone replaced rhe fuse box with loose barrel type fuses-they had the push in and twist holders, just going everywhere. in other words I had a mess, and nothing worded except the engine ran. It even ran when the main switch was removed! I had to use the emergency stop to shut it down. I bought a 5 flat fusebox type (modern fuses) and did it according to the schematic for this bike. It works perfectly now, and to see those dash lights come on when I turned the key on! I was feeling quite chesty like a rooster, by Gumby! Guys, it is important to check this out if you are having electrical issues. I was going to buy a whole wiring harness and replace all the electrical components. I had a time trying to figure out all the problems, and it turned out that Mr. Finger touched it in the past. I read here about the front turn signal doubles as a running light. One is out, so I was thinking that I still had a problem, but you righted me out on that. I did have the carb vent bowls pluged and spent a lot of thime trying to find why *4 carb was leaking gas. I fixed that according to someones blog. This vent tube is important guys.
    question: the large vent tube on the front of the breather box is for the crankcase, but where is the vent tube on the engine? I cant seem to find it.
    I am charging the battery, and then I will take it on it’s first ride-in abouty an hour. The wheather here in PHX is perfect for a test spin on this day of May 17, 2014. Thanks!!

    • That large crankcase vent tube from the air box goes onto the barb that is facing sideways on the small cover at the back topside of the engine. it’s right above the oil fill hole and the barb faces the trany side of the engine. I’m glad you are finding this blog and other blogs about these bikes helpful.

  17. Raymond Sostarich says:

    Dam-I forgot to proof read my comment-Sorry!

  18. dan says:

    Hello! Just got my 79 xs1100 and once it warms up a bit the idle is running at 3000rpm. Cant kick it down. I was told there is a master idle adjustment screw somewhere by the carbs but i cant find it. Any help? Maybe a sketch or pic of what im looking for?
    Also anything else you think i should check as well to address the problem, thanks!

    • On all the XS1100 Carbs there is a large master idle adjustment knob (about ¾” DIN) right in the middle of the carb bank. It is typically on the back side between carb 2 and 3. Before you use the master adjustment knob be sure the carbs are well cleaned and ideally they will have been synced while the engine is at full operating temp. Also make sure there is enough free play in the cable and that the cable is not binding anywhere along its length.
      Note when working with the carbs and looking for specs, that in many cases the carbs may not be original to the engine.

  19. DOUG PERTNER says:


    • I’m not sure if what your mean? Are you saying that when you push the start button the starter spins but the engine does not but will when you put it in gear?

      • DOUG PERTNER says:

        Are you saying that when you push the start button the starter spins but the engine does not but will when you put it in gear? NO,THE ENGINE CRANKS OVER JUST FINE.

      • The natural switch is not inter-connected to the clutch in any way. The natural switch connection is under the engine on the timing side of the engine. The wire for it is spliced into the pick up wire harness. That being said, perhaps the clutch cable is routed in a fashion that when it flexes under load, it is affecting the harness along it route. Check the wiring along the cables route closely for disconnects / breaks under the insulation.

  20. Rich Davis says:

    Ok, hears what I’m doing. It’s raining out and I got on garage so I’m stuck in the shed with my ideas and thoughts.. I’ve been thinking about putting a XV750 Virago rear wheel on my 78 xs11??? If it wasn’t raining I’d be ripping in to this job even if it was wrong… lets have a clue man… cool place you got here mister…

    • I’m not familiar with the XV750 so I can’t comment on potential fitment to the XS11. That being said I don’t think this will be a straight swap out but just about anything is possible with planning and time. Why do you want or need to do this?
      Best opportunity would be if the XS11 wheel gear will bolt right onto the XV750 wheel. If not you are looking at a pretty big job unless the shaft parts are a match which I would think will not be the case. Good luck with this and keep us posted.

      • Rich Davis says:

        I’m thinking the same with the wheel gear. but what got me started is this. I’ve been reading that the 750 rear gear will lower the R.P.M.’s on the xs1100. Now I did just read that with this swop I might have to stretch the drive shaft??? another thing I’d like to know is, would you have any info, ( if any) about any inverted frontends that might inter change with the xs11? Thanks Rob… Richie-D….

      • I didn’t look into inverted forks or changing the forks out on my hop up bike because I wanted the bike to still be identified as an XS11. If you opt for inverted forks or want to change the forks out for something beefier the trick is finding forks that are fitted into a triple tree that will fit the XS11 head stock. Length and bearing mount points / size are the most importance. Have you been over to There’s loads of info over there on everything that is XS11. There is also an Australian site where these bikes remain popular. Whatever you do with the rear end try not to give up too much of the XS11s classic torque.

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