Adjusting clearances on all four intake valves by removing cam shaft?

[sacruickshank]

Checking valve clearances on my '83 650L project led to all four exhaust at .05-.06 (within spec) and all four intakes at less than .02 (too tight).

Since it's all four on the same shaft, is it possible/reasonable to release the intake cam shaft and do them all at once? If so, should I release the cam chain tensioner as well?

If not I'll do them the traditional one by one method, using the Suzuki tool and/or zip tie method. I have 7 spare shims, so hopefully the sizes will work out.

Thx

 

[Redman]

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Since it's all four on the same shaft, is it possible/reasonable to release the intake cam shaft and do them all at once? If so, should I release the cam chain tensioner as well?..

Not sure what you mean by "release" the tensioner (since it should be what I would call "released" already).

But if you remove, or just lift up some, any cam shaft you will have to do something with the tensioner, because once you create some slack in the cam chain the tensioner will extend (but not go back in).


So probably what you will want to do,if do anything, is one of two things:
1: lock the tensioner in place with the lock screw, mess with cam, replace cam, unlock the tensioner. but if it slipps any at all, you will have to remove the tensioner and reset and reinstall.
or
2: remove the tensioner, mess with cam, reinstall cam, reset the tensioner, reinstall the tensioner and release the tensioner.

 

[sacruickshank]

Not sure what you mean by "release" the tensioner (since it should be what I would call "released" already).

But if you remove, or just lift up some, any cam shaft you will have to do something with the tensioner, because once you create some slack in the cam chain the tensioner will extend (but not go back in).

So probably what you will want to do,if do anything, is one of two things:
1: lock the tensioner in place with the lock screw, mess with cam, replace cam, unlock the tensioner. but if it slipps any at all, you will have to remove the tensioner and reset and reinstall.
or
2: remove the tensioner, mess with cam, reinstall cam, reset the tensioner, reinstall the tensioner and release the tensioner.

Thanks for thinking that through. Accessing the tensioner for adjusting or resetting is difficult with carbs in place, so I'll go with the normal 1by1 method.

 

[Guest]

If you put a coin (nickel or a quarter) in place of the shim, you can remove all four at once. Then you can look at your shims to find the thinnest one. Put that one in each position, measure the clearance, and you will KNOW what size shim you actually need.

 

[sacruickshank]

If you put a coin (nickel or a quarter) in place of the shim, you can remove all four at once. Then you can look at your shims to find the thinnest one. Put that one in each position, measure the clearance, and you will KNOW what size shim you actually need.

Thanks for the hint, plus i've got a bunch of spare shims, so coin approach probably not needed. I'm pretty sure they all just need to go one size thinner. A .02 feeler gauge fit under one and all four bucket/shims turn easily as the exhaust ports with no contact. I realize turning still possible with some contact, but they spin freely enough that any contact is likely barely touching.

 

[Gorminrider]

Not sure what you mean by "release" the tensioner (since it should be what I would call "released" already).

But if you remove, or just lift up some, any cam shaft you will have to do something with the tensioner, because once you create some slack in the cam chain the tensioner will extend (but not go back in)....

.

...assuming your tensioner is similar to my 650, No. If you turn the Big Knurled Knob on the side of the tensioner it allows the tensioner blade's plunger-shaft to 'go back in" if it wants. However if the set screw is in the correct setting* (1/4 to 1/2 out from tight against the shaft) its retraction is limited by the indent on the shaft catching that set screw. But it should be enough.

You don't need to remove the cam. Just lift it enough to get shims out while turning the Big Knurled Knob, and it will slacken the tensioner blade as you lift the cam . You could then lock the tensioner blade's shaft until you are done. (If it seems not enough you could possibly turn out the set screw to clear the indent, but you would want to be sure that the plunger shaft had not turned when putting things back right. You could tell it was ok if the set screw turned in a little more as it met the indent's void )

* and it should be if the tensioner was assembled correctly-there is a flat spot on the shaft .

 

[93Bandit]

Just my humble opinion, but I think pulling the cam is more work than just checking clearances the traditional way. Not to mention pulling the cam opens up the possibilities of something going wrong because it's unnecessary additional steps.

I have the suzuki special tool and it's really quick and easy to use. Some on the forum prefer the zip tie method, but for $15 I think the tool is cheap and easy enough to use, no sense in fiddling around with zip ties. Some say the tool is finicky to use, but I've never had an issue.

 

[sacruickshank]

thanks all. I found an old Suzi tool and it worked fine on the intakes, which is all I really needed.

Current state is:
Exhaust - All four at .05-.06 using existing shims. On the low side of spec, especially for exhaust, but I didn't change any
Intake - Adjusted all four. #1, 3, and 4 now in spec at .07mm. #2 at .114 since I had a 2.55 shim but not a 2.6.

Unless this crowd thinks a clearance of .11 is OK I'll look for a 2.6 shim to get #2 closer to the others. I have plenty of time since I'm about to enter gasket cleaning hell.

 

[RustyTank]

Just my humble opinion, but I think pulling the cam is more work than just checking clearances the traditional way. Not to mention pulling the cam opens up the possibilities of something going wrong because it's unnecessary additional steps.

I have the suzuki special tool and it's really quick and easy to use. Some on the forum prefer the zip tie method, but for $15 I think the tool is cheap and easy enough to use, no sense in fiddling around with zip ties. Some say the tool is finicky to use, but I've never had an issue.

What is this Suzuki special tool? Someone drop a link if it's available please.

 

[sacruickshank]

What is this Suzuki special tool? Someone drop a link if it's available please.

https://www.ebay.com/itm/392639250637?fits=Make:Suzuki&hash=item5b6b1f80cd:g:7QQAAOSwpr9eGECJ

 

[Nessism]

thanks all. I found an old Suzi tool and it worked fine on the intakes, which is all I really needed.

Current state is:
Exhaust - All four at .05-.06 using existing shims. On the low side of spec, especially for exhaust, but I didn't change any
Intake - Adjusted all four. #1, 3, and 4 now in spec at .07mm. #2 at .114 since I had a 2.55 shim but not a 2.6.

Unless this crowd thinks a clearance of .11 is OK I'll look for a 2.6 shim to get #2 closer to the others. I have plenty of time since I'm about to enter gasket cleaning hell.

.11 mm is fine. Kawasaki engines with shim over bucket use .15 clearance. I wouldn't mess with it.

 

[Burque73]

thanks all. I found an old Suzi tool and it worked fine on the intakes, which is all I really needed.

Current state is:
Exhaust - All four at .05-.06 using existing shims. On the low side of spec, especially for exhaust, but I didn't change any
Intake - Adjusted all four. #1, 3, and 4 now in spec at .07mm. #2 at .114 since I had a 2.55 shim but not a 2.6.

Unless this crowd thinks a clearance of .11 is OK I'll look for a 2.6 shim to get #2 closer to the others. I have plenty of time since I'm about to enter gasket cleaning hell.

If you want I'll toss a 2.6 shim in the box with the other stuff when I send it. You'll need it eventually. My 850,s shims are all down below 2.55 now.

 

[sacruickshank]

If you want I'll toss a 2.6 shim in the box with the other stuff when I send it. You'll need it eventually. My 850,s shims are all down below 2.55 now.

Sounds good and thanks.

 

[sacruickshank]

...assuming your tensioner is similar to my 650, No. If you turn the Big Knurled Knob on the side of the tensioner it allows the tensioner blade's plunger-shaft to 'go back in" if it wants. However if the set screw is in the correct setting* (1/4 to 1/2 out from tight against the shaft) its retraction is limited by the indent on the shaft catching that set screw. But it should be enough.
<snipped text>

@Gorminrider - Are you saying that if the tensioner is currently installed correctly, the camshafts could be removed without having to remove and reset the tensioner? I'm asking because I'm now in the gasket cleaning phase (a.k.a petrified gasket hell) and it *might* be easier if the camshafts were removed.

If the tensioner has to be removed & reset then the carbs will have to come off. Not the hardest thing since the related rubber bits on the bike are in good shape.

If I want to really take the plunge I could take the entire cylinder head off, but than the head gasket might get damaged further extending my sentence in gasket hell.

 

[Nessism]

If you were to loosen the tensioner set screw locknut, then crank down the set screw to lock the tensioner plunger in its current position, you may be able to pull the cam at that point. I say "may" because I'm not sure if you will have enough slack in the cam chain at that point. It won't hurt to try though.

 

[sacruickshank]

If you were to loosen the tensioner set screw locknut, then crank down the set screw to lock the tensioner plunger in its current position, you may be able to pull the cam at that point. I say "may" because I'm not sure if you will have enough slack in the cam chain at that point. It won't hurt to try though.

Thanks. Now the conundrum is if I should do that at:
1. When the "1" arrow mark on the exhaust cam is pointed forward. The cam chain is relatively tight (i.e. less available slack), but this is the official assembly reference
-or-
2. Find a spot in the cycle where the cam chain is relatively loose, providing the most possible slack but more adjustment would be needed during re-assembly.

My initial guess is #2 since chain slack may be an issue anyway. Or maybe tighten down the set screw while in the position described in #1, then rotate the crank to a point of maximum slack. Risk is that the change in chain tension causes the chain to jump a tooth. Or maybe I'm dwelling on this too much.

Any recommendation?

 

[Gorminrider]

@Gorminrider - Are you saying that if the tensioner is currently installed correctly, the camshafts could be removed without having to remove and reset the tensioner? I'm asking because I'm now in the gasket cleaning phase (a.k.a petrified gasket hell) and it *might* be easier if the camshafts were removed.

If the tensioner has to be removed & reset then the carbs will have to come off. Not the hardest thing since the related rubber bits on the bike are in good shape.

If I want to really take the plunge I could take the entire cylinder head off, but than the head gasket might get damaged further extending my sentence in gasket hell.

I can't remember if I locked the tensioner in place. Could be a big help. Can't remember how i held the cams up while I fiddled but that'll be obvious anyways. Wooden sticks come to mind but there's lots of rough casting so a screwdriver can do

It's been two or more years since I went through the exercise of lifting the cam to read all the shims,write a table for future reference, and swap some around. You don't need much room . I remember needing two shims after that but it would have been more without the cunning swaps ...I remember doing what i describe but I can't remember much more except winkling the shims out of their buckets against the oils suction (the buckets rotate to a good spot) and swapping them around.
I don't remember it NOT working and having to remove the tensioner, but hey, try it because it only takes a minute and you're going to remove the tensioner anyways if I'm wrong in memory. ..so Yes, that's what I'm saying. The cam chain tensioner rod is itself spring-loaded to always be pushing into the engine against the blade, but pulling the loosened cam upward (or idea: maybe just pushing the top of the tensioner blade if it's accessible in the tunnel) can exert enough force along the chain to push it in enough to give you enough slack...

 

[rphillips]

Hey, Changing 4 shims isn't a big deal. Removing & replacing cam, replacing 4 shims & getting everything back together properly is a much bigger deal. As always, Just my opinion.

 

[sacruickshank]

I already have experience removing both cams, tensioner, and the cyl head before on my 550T ... and successfully getting it all back together and running properly. I know I can do it, just trying to minimize effort where appropriate and possible.

My 650L project is currently at the cyl head gasket scraping phase, so removing cams would mainly be a precaution to avoid accidently hitting a cam lobe with a scraping tool. Will try removing the cams while leaving the tensioner installed since removing the tensioner also requires removing the carbs.

 

[rphillips]

Oh OK, I didn't realize you had already BTDT & know what's involved. Just be sure the tensioner "is locked down good" before taking anything loose.