Removing Cams - Question

[Radioguylogs]

Over the past few years, my SF has become a mosquito fogger when it is started after sitting a month or two. The left exhaust smokes, but not the right. Last time I started it in August, it was so bad, oil dripped out the left exhaust drain hole. After it gets completely warmed up, the smoking stops.

So, I can't ignore it any longer. I need new valve seals.

I have procured a Vesrah gasket set and I am already disassembling the bike.

I have been reading ahead before I pull the head.

I have a question:

How do you remove the four bolts that hold the chain sprockets on the cams without bending any valves?

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Here is what the FSM says:




So, how do remove the four bolts when only two bolts are exposed, yet you have to rotate the engine to access the other two bolts.....but it says not to rotate the cams?!?
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Here what Clymer's says:



So how is one supposed to rotate the engine 180 degrees without rotating the cams? What good is rotating the engine if the cams don't rotate to access the other two bolts? [Really one should merely rotate the crankshaft, not the engine.]

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So, it seems the normal procedure is to remove two bolts at TDC, then rotate the crankshaft just enough past TDC to access the second two bolts and remove them? No valves will be bent?

Would it be better to go to TDC, note which two bolts are exposed (leaving them alone), then rotate the crank until you can remove the other two bolts. Finally go back to TDC and remove the two bolts that were originally exposed?

Your wisdom is appreciated.

[LenB]

"Would it be better to go to TDC, note which two bolts are exposed (leaving them alone), then rotate the crank until you can remove the other two bolts. Finally go back to TDC and remove the two bolts that were originally exposed?"

That sound right from when I replaced a cam chain - had to create enough slack, with the tensioner removed, to get things back in place. As long as you're not turning the crank with the sprockets off, you're OK. Had issues with worn intake valve guides and oil burning/consumption when the bike was still under warranty - check for any excess play when you have the springs off. Was bored 1 over because of wear while they were in there, too. Up to 1109cc from 1103cc? Wasn't part of that conversation or it would have been bigger than that. Good luck with the tear-down Mike - you won't get bored this winter!

[bikerphil]

I just removed cams not too long ago. I took out the spark plugs. I put crank to TDC (cam alignment marks 180 deg. from the arrows) and removed the 2 exposed cam bolts. Then rotate to next TDC (dots lining up with arrows) and remove the remaining 2 bolts. Take out the tensioner and remove the cams.
Then, when it's time for reassembly, timing marks will be aligned.

[cajun31]

Michael, Crazy Steve gives a good pictorial of what Phil is describing here: Valve Adjustment Pictorial - XS11.club Forums.

[Radioguylogs]

Thanks LenB and bikerphil.

My biggest worry was that when I removed the cam chain in a different location from TDC, the cam lobes would slide downhill due to valve spring tension. That valve would close, but another valve might open and hit a piston.

I like bikerphil's idea that has the timing marks left in an ideal spot for re-assembly.

I should check the valve guides for looseness as LenB alluded.

The advice from both of you is very helpful.

[cajun31]

How old is the cam chain? Might be a good time to replace with a new one. If so then just break the chain with the timing marks aligned and proceed with the top end rebuild. Is your compression still good? All I am alluding to is that if I were that far in I would go ahead and replace the cam chain too.

[Radioguylogs]

How old is the cam chain?.

45 years old .

The bike has 23k miles on it. I haven't checked the compression recently, but I am sure it is good.

I was thinking more about replacing the piston rings, but you have another good suggestion.

However, with relatively low miles, I was thinking to keep the rings and chain if I can avoid disturbing the base gasket.

Has anyone tried using the engine compression to loosen the head gasket?

[bikerphil]

I wouldn't worry about the chain, 23K is nothing. If you did the auto tensioner mod, you can get over 150K, otherwise about 60K the stock tensioner runs out of travel.

The head gasket won't bind like the base gasket will, you shouldn't have any struggle removing the head.

[DiverRay]

With that low of miles on it, I would NOT worry about the rings. I think just replace the valve stem seals, de-carbon the head, and put it back together.

[Radioguylogs]

Michael, Crazy Steve gives a good pictorial of what Phil is describing here: Valve Adjustment Pictorial - XS11.club Forums.

Thanks Cajun !- Our messages passed in cyberspace and I didn't find it until now.

It's very helpful.

[bikerphil]

I agree with Ray.

[cajun31]

Thanks Cajun !- Our messages passed in cyberspace and I didn't find it until now.

It's very helpful.

Pictorials are worth thousands of words. Concerning the cam chain. I am not disagreeing that the chain is good with those low miles but just wanted to point out that a new chain can just be slipped in place without much effort once you get it torn down to the point of removing the cam sprockets you can follow this tech tip to just get a new chain installed. Cam Chain Tips - XS11.club Forums. Depends on how much effort you want to put into it and how your funds are holding up. Mind you ... not a need too but what I call a nice to do thing. It also depends on how many miles you do a year on your bike.

[Radioguylogs]

Ready to do the deed. Everything is ready to remove the cams and head.

#1 is the problem child. The other 3 cylinders look fairly normal. I'll post pictures of the evidence tomorrow.

All the valve clearances are all still in spec after 8k miles. In fact, they seem to be in the mid to high range of the spec (more gap).

[Radioguylogs]

Three of the exhaust ports look OK, with a little seal leakage. Number 4 is representative among 2/3/4:






Number 1 is obviously the problem:

[bikerphil]

Looks like all the oil coming from the valve seal and not from rings.