Yamaha Virago xv750 Engine Rebuild: Part 9(Final)-Engine Reassembly 

Thanks man ! Glad the videos helped some 👍. Great to hear that another one of these great bikes was rescued versus just parted out or thrown away 👍. All the best ! Steve

Joel Coutant , Bonjour Joel !! Merci beaucoup 👍

Thanks man ! The motor is still running strong after the rebuild…looks like it will be a solid runner for many more years to come 👍. Thanks again and all the best ! Steve

Hey man ! I’ll have to check on one of my parts motors, but I think the oil pump bolts go all the way through to the other side so you’d have to remove the flywheel to take them out. I’ll look to be sure, but if there aren’t any bolts behind the flywheel, theoretically you could remove the right side case with the flywheel in place since the crank can stay with the left side of the motor. I’ll have a look tomorrow and let you know 👍

Hey man, I believe the spec for the four bigger nuts that hold the cylinder heads to the cylinders is about 36 ft-lbs…the nuts that bolt the front cylinder to the frame bracket are torqued the same or a bit more. Since the aftermarket head gaskets for the 1st Gens tend to run a bit tall and don’t like to squish down good, I usually end up at about 40 ft-lbs for them though I believe and still have a little gap between the heads and the cylinders. After a few rides, I’ve noticed that the gaskets will compress on down from the heating expansion and then cooling so my initial 40 ft-lbs reduces and is closer to the spec again.

Hey man ! Glad the videos are helpful 👍. I actually just pulled the motor from a ‘85 xv1000 parts bike I got a few months ago. Other than the side bars that hold the foot pegs on the 1000 that are not there on the 1st Gen 750 and the bolts at the lower back of the motor that bolt up to the frame vs. the aluminum triangular plates, the motors come out virtually the same and the motor doesn’t need any disassembly. If I remember right, once the breathers, fuel lines, exhaust pipes, and the wiring is disconnected, there are only a few bolts that actually hold the motor to the frame. There are two long bolts above the front cyl. head that go through the frame and bracket bolted to the head, then there are two bolts above the rear head to the frame. At the lower back of the motor case there is a bolt on each side that holds it to the frame, then one really long bolt toward the bottom (still at the back of the motor) that has to come out. Once these are all removed (with something under the motor of course), the motor can be wiggled side to side and the drive shaft spline will slide out of the motor. Don’t forget to pop the big rubber boot that keeps debris out of the drive shaft to motor connection free from the motor (has little pull tabs on it). It will make you think something is still holding the motor although it will wiggle and pull forward just a little. I haven’t made a video of pulling just a motor, but there is a time lapse for a Cafe build I did that shows me taking the motors off, then putting it back. It should be in the xv750 playlist on the channel as well. Hope this helps a little 👍. Steve

@@StevesDIYs Thanks Steve, this is very helpful, I'll get back into it tomorrow and see how I go.

Hey ! I believe the brand I used was “NE Brand” for the complete gasket kit. The head gaskets were a bit thick, but since they made to compress and fill the gasket groove when the heads are tightened, they did fine. After the final head torque, there was still a slight gap between the heads and the cylinders, but I noticed after a few rides, the heat expansion compressed the gasket on down and the gap went away. Hope this helps a bit and all the best ! Steve

Hey man ! The cylinder with the crank case vent pipe connection on the cam cover is the only one that has the splash guard in the inside. For some models though, the vent is on the front cylinder like you said. I think it depended on where Yamaha put the vent connection to the frame for which cylinder it went on. Hope this helps and all the best ! Steve

Thanks man ! There are some marks on the top of the cylinders bodies, but I don’t believe they designate which is front or rear. Seems like they were something like Y-2 or Y-1-2, but not sure what they are for. I don’t think there is a difference between them like the heads (the heads have different cams for the front and rear so those have to be put back the same). For the couple of parts bike builds I’ve done where all of the pieces were in boxes, I usually look for things like road tar/little rocks to tell which had been on the front or if someone had painted the motor, the rear is usually not painted very well if they did it on the bike. I don’t think it matters though, but I’ll usually try to put them back together the way they were originally.

Hey man ! Yep, since the tensioner is self adjusting (it takes the slack out of the chain as it stretches over the years), you first have to remove the little black rubber piece (or just remove the two screws and remove to outer cover), and take a flat blade screwdriver and retract the plunger by turning it. While you have the plunger held back with the screwdriver, you then can mount it on the motor and tighten the bolts that hold it on. Even if you slip with the screwdriver once you get the two bolts started, you just have to rotate the plunger again so the adjuster can press up to the cylinder and continue tightening the bolts by hand till they are tight. Once you get ready to do the final tightening on the bolts, just be sure you once again take the screwdriver and rotate it so the plunger is retracted the whole time you are tightening the bolts. When the bolts are tight, you can release the tensioner and it will press in to take the slack out of the chain once again. Hope this helps…if that wasn’t the part you were referring too, just let me know and I can try to explain more. Thanks and all the best ! Steve

@@StevesDIYs nope, you explained it perfectly. I was trying to understand it without looking at the damn thing but once I looked and fiddled with it, I knew exactly what you meant lol. I will hold back from questions for the time being. Front cylinder fully rebuilt, just looking to do the rear now. You're a lifesaver!

@@kodymorland3678 , Thanks man and glad the info was helpful 👍. Just let me know if you run into something and I’ll see if I can help 👍. All the best ! Steve

dzięki !

Deryk Rivera , hey man. Parts 2 to 4 of the series show the removal of the head and cylinder if you wanted to look at those. If you are just removing the head you would have to be careful not to drop the chain down in the cylinder so hooking a wire on it helps. If you are also taking the cylinder off it’s not an issue if the chain gets slack because you can easily retrieve it (it doesn’t have anywhere to go really). As far as the chain having to stay in the same teeth on the gears on the bottom gear it’s not necessary...there are no marks on the chain to set the timing so it doesn’t matter. What’s important is making sure the bottom gear is timed with the cam gear when installing. The first video in the series shows how to check (set the timing) and when I was putting the heads back on in Part 9 it shows how to jump the chain on the cam gear to get the gears in position. Hope this helps...all the best, Steve

Steve’s DIYs also would you know the torque specs for the four bolts on the head and the 5 Alan bolts

Deryk Rivera , hey again...for the xv700 and xv750 models, the manual calls out for 36 ft-lb for the 1st step on all of the big head nuts followed by the final torque of 46 ft-lb. For the two acorn nuts it is 29 ft-lb and for the 8mm bolts it is 14 ft-lb. The three jug bolts are 6mm so they typically torque to 7.2 ft-lb for that diameter bolt. Hope this helps 👍

Hey ! For the xv750’s, the 10mm head nuts torque to 40Nm or 29 ft/lbs per the manual. All the best ! Steve

Yep, at about the 1:26 minute time stamp I’m smoothing out the Case sealer ( I probably should have noted that it is the Gray case seal as now that I’m watching the video you can’t really see it since it looks like the aluminum in the video). It’s a thick paste type case seal I use on transmissions and transfer cases for autos. Good eye 👍. Hopefully folks will see these comments and it will be clearer.

Hey man ! From rebuilding my three over the years, I’ve found that a small gap is sometimes there (like .010”to .015”) and I think it’s due to the differences in head gaskets supplied in the kits. Some seem to compress completely while other seem to leave a little gap. As long as it’s a small gap and not leaking oil from around the irregular shaped oring that surrounds the hole where the cam chain comes up, I’ve not had any problems leaving a small gap. If it is a big gap on one side (I did have a rebuild do that once), I tried it and it leaked oil past the oring. For that one, I took the head back off, rotated the gasket 180 degrees and then torqued it back down to compress the gasket again and most of the gap went away and it was good. That was like 6 years ago and I’m still running that same head gasket (it’s on my stock bike) and everything has been fine. If you just can’t get it down to at least a very small gap, it might be worth it to get another set of gaskets from a different supplier to see if theirs will compress better. Another thing to check if you do pull the heads back off, is to make sure there are not any of the thin metal rings from the old one stuck in the thin groove between the steel cylinder liner and the aluminum of the head. The thin metal bands from the old gasket (if it had fallen apart) can get stuck around the cylinder liner and need to be completely gotten out with a pick or something so they are not holding up the new gasket. The thin metal rings get stuck in there really tight so it takes some patience to dig the pieces out for sure. Hope this helps and all the best ! Steve

@@StevesDIYs hey thanks for the reply. This makes a lot of sense. I actually did have some of those small burs from the old head gasket and did my best to get them out but some just wouldn’t budge. I ended getting different head gaskets and still waiting for them. The issue was, with the gap that mine previously had when I torqued the 2-3 head bolts down to spec it completely sheared my cylinder in half... I guess because the gap was too big lol. Hopefully all goes smoothly next time. I do have another question though, when you reinstall your cams, do they have to be inserted at correct angles for timing or can you adjust it after?

@@jackpistone8015 man, that’s a bummer ☹️...hopefully the reinstall goes better with the new gaskets 👍. For the cams, they just go back in any orientation...they really only fit in one way and will rotate back and forth just a little but not much when first installed. The back cylinder’s cam is different than the front cyl so they cannot be mixed up (you probably knew that, but just in case). When you set your timing to the flywheel marks you’ll be able to set them in the correct timing after you have the cam gear back on and tightened up with the little pin in that holds the gear positioned correctly to the cam 👍. I typically do the timing for one cylinder first before putting the gear on the other one’s cam (just loop the chain over the end of the cam with the bolt on it). That way it won’t rotate the other cylinders cam and make the valves move so they won’t hit the piston as I’m timing the cylinder I’m working on.

Thanks man, glad the videos helped some 👍. I’ve actually never swapped the heads to try it, but I’ve gone through the front and rear heads comparing the dimensions and like you said, I couldn’t find any differences other than the little “1” and “2” marked on them (for the 1st Gen 750 heads anyway). I’d say it would be worth a try to swap the cams and maybe the rocker arms to the head (in case they land on the cam differently or something) and assemble it all up (I would definitely try it if I was doing it 👍). I’d crank it around by hand after assembling just to be sure, but I always do that anyway after a reassembly. Hope this helps and all the best ! Steve

Well I reassembled the motor with a rear cylinder up front and cranking it over seemed to work fine. Cranking it with the starter I get 155 psi. The motor fires up but missed on the front cylinder and backfires through the carburator until you get past 3000 rpm then it runs with no miss firing. Odd thing with the cam timing is the cam is slightly ahead by 1 chain link of the alignment marker. So cam timing is slightly retarded. Moving the cam sprocket back by 1 tooth moves the cam marker 1 chain link ahead of the marker. So I cannot get the cam exactly aligned to the marker. Possibly the cam chain is worn or stretched? Maybe the chain guides are excessively worn? Anyway is either situation of advanced or retarded cam timing exceptable? Thanks Jeff

@jj57754 hey again, yep it does sound like the chain is stretched a bit if the marks aren’t lining up very good. For mine, I put the timing mark to the retard side (lagging the mark), just to be sure the valve doesn’t start coming down too early, but this probably takes a little power away from the motor. The most mine have been off so far is about a half a chain length which seems to be pretty normal for the motors with some miles on them. If you haven’t tried it, maybe turn the idle air fuel mix needle out a bit more to see if you can minimize the popping back through the carbs. Also (you may have already done this as well, but just in case) be sure to check the carb sync after installing the carbs on the bike to be sure they are pulling the same vacuum. This can cause a little popping as one cylinder is getting forced to run faster than the amount of fuel it’s getting.

@StevesDIYs Okay, I'll sync the carbs and adjust the idle fuel mixture needle for the front cylinder and see how that goes. I rebuilt the carbs but kept the jetting stock. With header exhaust, the front cylinder might be running lean, but I'll check the plug color. I might get a quieter exhaust canister insert, so I'm holding off on jetting changes for now. And, the pressure relief valve will likely go if there's a jetting change. Great video on this quirky valve. Jeff

Hey man ! Thanks...glad the videos help some 👍. For this motor in the video (and the other couple of these Gen 1’s I have), the head gasket does typically stick up out of the groove some in order to get tightly squished down for the seal. I’ve found that a little gap between the head and the jug (0.010” to 0.015”) doesn’t seem to hurt anything as that’s close enough to still allow the gasket that goes around the hole where the cam chain comes up to still seal so it doesn’t leak oil from between the head and the jug. That’s really the only thing that having a gap hurts as long as the gap is consistent all the way around under the head. If the gap is really big even after over torquing the head nuts, it may be that the kit had the slightly too tall head gasket in it that some kits have. I think one company made them slightly taller than spec thinking these motors are older and the head groove would be worn or something (I’m guessing in that though). Years ago I ran into the same problem with having too much gap below the head (that’s how I know for sure they will leak oil, lol). I just torqued the head bolts again when I found the cause of the oil leak and it reduced the gap enough to stop the leak. I had run the motor several times trying to find the oil leak so that may have been enough settling to allow me to torque it on down. I’m actually still running on those head gaskets (it was my stock bike) and hasn’t leaked or anything since. Hope this helps and all the best ! Steve

Thanks for the reply! After reaching about 70 foot pounds on the head bolts and the head gasket compressing, but not enough to close the timing chain part, I decided to give it a rest and I ordered new head gaskets that are OEM and hopefully they will fit. I will try to remember to comment again because I can say what brand didn’t fit for me and what one did so other people know what to buy! Thanks man!

​@@yangwong5964 & Steve Thanks! I was working on front head yesterday and had the same issue. I able to tight the bolts way pass the torque specs and able to close the gap. I am afraid to work on rear now because it was not easy. Thanks Steve for your videos, they are very helpful.

Thanks man ! Glad the videos help some 👍. All the best ! Steve

Hey man ! No, the video didn’t show the two large copper (or crush type) exhaust pipe seals as they go on when the pipes are being installed when the motor is back on the bike. I usually will replace them if I have new ones that came with the gasket kit, but I’ve also reused the old ones if I didn’t have any extras 👍. They are kinda of tricky to get them to stay in the head since the port is tilted downward so I normally take a little grease and put it on them so they will stick to the head when putting the pipes back on. The small amount of grease will smoke a little when the motor is started for the first time, but it’s gone in just a few minutes. If the gaskets had been left out previously and the pipes tightened up, the bolts on yours may be bent as well so you’ll have a harder time getting the flanges back on them (that’s were the grease on the gasket makes it much easier as well so t stays in there when you are working to get the flange back on). For several of mine, the previous owner had tightened the exhaust flange bolts way too tight and they were crooked…I don’t try to bend them back straight though as they might break the head so I just push on them sideways until the flange goes back on the bolts. Another thing is that the short rear exhaust pipe piece with the flange needs to be in the frame prior to putting the motor back in (for 1st Gens anyway) as there’s not enough room to get the flange into the frame once the motor is bolted in. Hope this helps some and all the best !

Thanks for the info Steve. I got a screwdriver in there and found there were old copper gaskets in there, they were just black with soot. And I know all about the rear exhaust pipe from the rear cylinder. My dad helped me get the engine onto the bike this weekend and I was gutted upon the realization I couldn't fit it in. I was going to plan to take off the rear wheel instead of take the engine back out. Thoughts? I haven't had a peak at the rear brake pads yet or anything so I figure I might as well

@@kodymorland3678 Good to know they were in there from before as your bolts are probably not bent 👍. As for getting the rear exhaust pipe back in, I’ve never tried by taking the rear wheel off to do it, but it’s definitely worth a try vs. pulling the motor back off if you plan to have a look at the brakes and things anyway. It might be that the rear swing arm has to come off to get it back in (I’m really not sure), but if that’s the case, many times the swing arm bolt internal bearing race is rusted solid on these which makes for a terrible day if removal is attempted and it is. If you do try to take the swing arm off and the bolt doesn’t start backing out easily like a normal bolt should do, it might be best to just tighten it back up and save that for another day after getting a new bolt and bearing set for the swing arm. There’s another video on the channel in the xv750 playlist that shows how difficult becomes when the swing arm bolt is rusted up in case you wanted to see. All the best and let me know how you progress ! Steve

@@StevesDIYs Thought I'd follow up and confirm you definately can get the rear exhaust in place by removing the rear tire 👍

@@kodymorland3678 Nice ! Good to know that it can be done 👍. That is much easier than having to pull the motor out for sure. I’ll keep that in mind if I forget on a future build 👍. All the best ! Steve

Yep, there are tons of little pieces that have to go back in the right order...fortunately most go back in place only one way. Those dang cam chain tensioners do slip out if the pocket though and everything still bolts up even with them out of position. Its happened on two of the four rebuilds I’ve done so you would think I would have learned to check by now, lol. All the best ! Steve.

Hey man ! I’ve heard a few theories, but not sure if anyone can confirm since they were made so long ago. One is that they are vibration dampers for he bolts and the other is that they help guide the jugs down straight, but neither explain why there are none on the rear cylinder unless the angle of the front cylinder caused them to rattle and it didn’t on the back. Maybe someone else reading the comments knows from some past history 👍. All the best ! Steve

Thanks Steve! I had removed them after messing them up pulling the cylinder off. Planned to replace them with some shrink tubing but wasn’t sure the logic behind having them. Appreciate the quick response, and thanks for all the videos!

​@@StevesDIYs Steve, My buddy and I have really enjoyed your videos as a reference for a virago engine rebuild we are doing. Full custom bike with powdercoat We noticed one more thing that has me a bit concerned and wondered if you had run into this: A gap between the cylinder and the head. We put in new gaskets for the cylinder, same one you installed at 12:22 in this video. We tightened down all 5 bolts and the two allens in specified order using a pretty hearty breaker bar. Despite going full ape on it we still see a small gap between the heads and the cylinder. Is this normal? Will it fully seat with a few thermal cycles? Any tips? -Adam

@@adamlindsay2440 , hey man...thanks ! Glad the videos are helpful 👍. For the head gap, I’ve noticed it with some of the gasket kits being sold now. When I rebuilt my stock bike’s motor a few years ago I had the same issue...had about .015” gap on both heads after torquing them down. I wondered the same thing so I added a bit more torque over the spec thinking they would settle on in after some heat cycles like you said. Turns out that that’s just what they did 👍 and I haven’t had any problems out of them. For reference, I put a pic of the gap now (actually a pic of no gap now, lol) on my Facebook is page... here’s a link to it: facebook.com/109400450606405/posts/327974928748955/?d=n . If it’s a really big gap, some folks will take the heads back off and check to be sure none of the thin metal bands that make up the gasket are stuck down in the groove between the jug liner and the jug body...if that groove is filled up with remains from the last gasket, it will hold the new one up a bit higher. Hope this helps 👍, Steve

@@StevesDIYs super helpful. Yea I’m sitting at about 1/16th inch maybe less haven’t measured yet but that puts our collective minds to rest. Now on to the timing and the rest of the project! Thanks again!

Hey ! Was it not firing even before swapping to the single carb intake? These bikes are pretty finicky about the carb adjustments (Both with the OE ones or with a single carb) it seems. If you have good spark, good compression, and the timing is set correctly, it would almost have to be something with either getting too much air or not enough fuel. Based on the rear cylinder is firing when running on the idle circuit, but not when the butterfly opens up for the run fuel circuit, I’d say you might need to go bigger on the jetting or choke off some of the air for the carb with a baffle placed in the air cleaner to restrict the air. A good way to tell is to put your hand over the end of the carb and spread your fingers to let the air flow through them…then as you try to throttle up the motor, restrict some of the air and see if it lights up and the revs come up. If so, you are probably getting too much air for the amount of fuel the carb (or carbs) is metering. Hope this helps and let me know what you find out 👍. All the best ! Steve

​@@StevesDIYs i started messing with the carb needle and jet and ended up taking the intake manifold off and the rear cylinder is blowing air out of the intake while the front is perfect and played with cam gear maybe it was 180 out or off by 1 tooth but i cannot get the rear cylinder to not open the intake valve and exhaust at the correct time

@@Ghost-zo9qo hey man, looks like you are narrowing it down 👍. If it was 180 degrees out when the valve clearance was adjusted, the valves may not be closing at the right time or you might have either a bent valve or crud on the valve seat that’s allowing it to blow the compression back up the carb. There’s another video out on the channel that goes through setting the timing as well as the valve clearance if you haven’t seen if interested. It’s in the xv750 playlist as well. Hopefully you’ll get it figured out soon as I know how frustrating it can be with these bikes sometimes.

@@StevesDIYs broken flywheel key

@@Ghost-zo9qo Ahhh ! Well, that makes sense now on why the flywheel marks were off and the piston at the bottom 👍. Hopefully what ever caused the key to shear didn’t cause any damage to the other motor components. Seems like the metal of the flywheel key is pretty hard (not like an actual shear key), so I wonder what made it do that?

Hey man ! You’re talking about the thin black sleeves on the long bolts...right? If so, I’ve had a couple break apart over the years and I just use electrical tape and wrap the bolt where it was to replace it. I believe these are to prevent the long bolts from vibrating since they are smaller than the holes so nothing is really touching them in the middle (for the ones that don’t have the metal alignment hollow pins).

@@StevesDIYs That's exactly what i'm talking about. In fact the broken one made the jug a bear to remove. I'll give it a wrap-up! thanks much

Hey man ! If you want to you can go over to my Facebook page and then send me a message through Messenger with the video of what you have going on. Here’s the link to the page: facebook.com/stevesdiys/

Hola y muchas gracias ! Mi espanol is muy malo disafortunatemente. At the 9:48 time mark in the video, I place the head gasket onto the cylinder 👍. The 1981 through 1983 motors have just a round compression gasket that fits into a groove of the cylinder top surface versus the normal flat head gasket that resembles the shape to the cylinder top surface. Gracias una ves mas y All the best ! Steve

@@StevesDIYs fantastico steves ! entoces solo va un anilllo de aluminio? la mia es modelo 1982 y trajo junta de metal y amianto, es raro. tendre que fabricarlos verdad?

@@Daviddavid-hc4zi si, for the 1981 through 1983, it only has the metal ring. It is actually made of thin layers of metal with thin layers of asbestos in between the metal so it can compress and take the shape of the groove it sits in. There is also a shaped rubber oring type seal that goes in the groove where the timing chain comes up to the head from the cylinder.

@@StevesDIYs ok steves!! aqui en argentina no se consigue, crees que puedo fabricarla solo de aluminio?

@@Daviddavid-hc4zi Hola ! If I was planning to make one, I would use copper versus aluminum for the head gasket ring since copper deforms much easier than aluminum. Using copper would allow it to compress into the groove and also fill into any marks or rough spots on the surfaces. If you make a copper one, be sure to heat it up to soften the copper (annealing) so it can easily be compressed when the head is tightened. The 1970’s and older vintage Indian brand motorcycles used a copper head gasket and worked very well. It was also nice that the copper head gasket could be reused by removing and heating it up with a torch to re-soften the copper and then reforming it so it would seal again. Hope this helps a bit and all the best ! Steve

Hey man ! Sorry, but my Portuguese is very limited, but it sounds like you had a connecting rod fail? If this is what happened, then the ticking noise could be a slightly bent valve that still looks like it is sealing or even the rod bearings or wrist pin making a tapping sound. Have you performed a compression check to see if you are still getting good compression after the rebuild? This may help to be sure the valves are sealing properly. Also check to see if you set the valve gap with the crank and cam in the correct position (the flywheel on the marks for the head and then the cam with the arrow on the gear pointing up towards the mark on the head). The first part of the motor rebuild video series I did shows how to set the timing to verify the valve gap it if needed. Sorry I can’t help much, but it’s very difficult to tell what the issue might be if the motor had some damage.

@@StevesDIYs Obrigado amigo, realmente o motor estava ok e apos romper as bronzinas e depois de montar ficou com este barulho tipo de valvulas so que mais acentuado isso no cabecote do mesmo lado onde houve o problema com a biela, uma coisa que nao foi posto foi os guias dos parafusos deste cilindro traseiro. mas removi novamente e troquei o cabecote e coloquei fita isolante como guia vou montar e testar. espera que tudo de certo, mais uma x obrigado.

@@felipematzembacher9275 , thanks man ! hopefully it will be fine and it is just some normal tapping sounds that these old motors make. All the best ! Steve