Somewhat scared and apprehensive

Mickster

XS650 Enthusiast
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The bike is running good. Compression is strong on the kick pedal. All systems seem to be OK.

Except for the smoke out the right side exhaust and a bit less out the left side. At Idle all looks good, crack the throttle and white smoke comes out on the de-cell.

Read that Re-torqueing the heads hoping it was a leaking gasket would help. Nope.

Now it's time to pull the motor out of the frame, and do a top end. Which is sort of freaking me out. All this data on this site regarding the cam and chain and how to get through it all is not anything like a push rod motor which is easy.

Valve seals and rings. Re-use the piston, ball home the cylinders. I'm hoping that's all it will take to get this motorbike squared away.

I don't want to screw this up, want to get right, no leaks, no issues. What do you guys think I should do?

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Smoke on decel is almost certainly valve guide seals. Although slightly harder than a pushrod engine... it's still a pretty easy top end. If you've done one you can do the other. Have a read through the Top End Buildup thread in Tech. I've never used it, but I've heard tell it's pretty good. :rolleyes:
 
You can replace valve guide seals without taking the engine out of the frame or disassembling it. There are a few threads on this. One is here:
https://xs650temp.proboards.com/thread/12269
I have done this two or three times. It's a little bit slow and tedious, but a lot faster and easier than the alternatives.
 
I don't think you can get the cam cover past the frame with the engine in. Sorry.

It's only a handful of bolts and a backache away from coming out though!
 
Working on these is pretty easy. Hardest part to me is getting the cam chain off and on the cam. Well after getting the motor out of the frame. That part is a pain in the backside.
 
Sounds like getting the motor out of the frame is the big stumbling block. Bought my XS a year ago and ended up lifting the engine out of the frame on my own - dam near did meself an injury. Vowed I ain't doing that again, so I got two helpers when lifting it back in again. Since then, bought a block and chain & since then have done an engine swap. It was a lot easier with the block and chain.

With the engine out, sorting the valve guides or whatever else is needed will be straightforward. Lifting the chain off the cam is not difficult - just doesn't help if you let it drop down inside the motor. Don't ask . . .

You'll be alright.
 
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Before you go anywhere, you say white smoke, white smoke is water vapor, and if it is just that your bike needs a good run and heat through, if your smoke is blue it's oil and could be rings, stem seals or head gasket, if black smoke it is un-burnt fuel, best to truly establish what sort of smoke you have first this may save you from an expensive tear down.
 
Dealing with the cam chain and cam timing does seem intimidating at first, but it's all pretty easy and straight forward once you're in there. You simply place the motor at TDC, set the cam in with it's index mark pointing straight up, and install the chain. Put the master link in but don't rivet it yet until you've verified the marks are right. If you're re-using an old cam chain, you need to set the cam chain tensioner because that will roll the cam backwards a little. That may throw the marks off and require you to jump the chain a tooth.
 
I'll repeat what I said in my previous post:
You don't have to take the engine out of the frame or disassemble it to change the valve guide seals.
https://xs650temp.proboards.com/thread/12269
He's near you, close to Bastrop.
If I was going to do seals with motor in I would first make sure the problem is the seals. You should be able to squirt oil and let it run down the valve stem and see if it makes it worse. Also, it seems to me that it should be worst on startup, as yesterday's oil that ran down the stem after shutdown burns off.
Also, the exhaust seals are more likely shot than the intake. With motor in, I'd do the exhausts first and look at the result. Another alternative if it isn't a smoke bomb and your plugs don't foul is leave it be. If you pull the engine and re-ring it, there's an argument to be made for doing nothing at all to the cylinder walls. And another argument for doing nothing or a least going very lightly on the valves/seats. Oil consumption will depend pretty much entirely on how hard your new rings press against the cylinder walls -- something that varies a lot
 
With all the help and encouragement I've gotten from you guys me thinks I'll be able to pull this off. Excellent tutorials, excellent advice.

Today's ride warmed it up to operating temp. Parked it in neutral and held the throttle at 4000 rpm. Right cylinder smokes like an old 2 stroke, left cylinder very little. On de-cel more smoke.

It's valve seals, or rings, or most likely both.

I found this bike after sitting out in a posture for over 5 years. When I got it running it was smoking some and I was hoping it was the rings not set and riding it would make it acceptable. After about 600 miles of riding it around, it still smokes. I added Mystery Oil, Seafoam, you name it and of course none of that did anything.

Because I did all the cosmetics, replaced all sorts seals, rebuilt what I could, it's not a bad lookin or runnin motorbike. The clutch, trans, electrics are all in good shape. I think it's worth it to put in some time, money and effort to make it right. And if I run into trouble I'll ask you guys for some help. There's even a shop or two around here that may be willing to help out. I read that DogBunny is around not to far away.

I'm going to jump in and yank the motor. Take the top end apart. Replace rings and seals. Assess any other things to be replaced and hope for the best.

And yes I agree, that Shamu paint job is very relaxing.

We love pics so here's how it looked when I got it home. It's a 79 with an 81 motor based on the numbers.

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