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Discussion Starter #1
Seem to be missing some of my service manual pages (including the damn index) for the life of me I can't find anything on the adjustment procedure.

basically, I guess my question is are the clearances measured at tdc for each piston, or where the each cam lobe is pointing directly away from the shim? definately a different value, and as 4 were adjusted at 17k miles, and it's now at 46k, I wouldn't be surprised if they are all out of spec...

and those those who have done it (I've only ever done vavles on tappet style engines) the goal is to be on the higher end of the service gap between the lobe and shim as the vavles tighten up over time, not to mention the thicker shims mean more valve movement.

I measured them all at dtc for their respective piston, but want to make sure I measured correctly before I start pulling cams.

fortunately the rear shock is getting serviced and new head bearings are sitting around, so clearly it's not going anywhere anytime soon :dowhat

appreciate the info from those that have done this before.
 

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According to the shop manual:
The tappet clearance should be taken when each cylinder is at Top Dead Center (TDC) of compression stroke.
The manual shows a photo of the relative position of the cams where you can check the clearances in the above scenario. The cams on the front cylinder (both intake & exhaust) should be facing either forward (intake) or to the rear (exhaust). So if you look at the drawing they provide the intake cam lobe is facing outward toward the throttle body & the exhaust cam lobe is facing outward toward the exhaust pipe. If they are in this position they are at TDC on the compression stroke. If you have adjusted Suzuki shim under bucket valve trains before you know the cam lobes that you can check/adjust are either facing straight up or off to the side. This is a little different than that found on older Suzuki engines. On the rear cylinder the cam lobes are canted inward, toward each other when that cylinder is at TDC on the compression stoke. So on that rear cylinder the lobes are facing the opposite direction than the front cylinder's on the compression stroke at TDC.

Sorry no pictures, camera is full of shots of old Mopar muscle cars I took today at a Mopar car show. If I posted a picture of an engine it would be of a 426 Hemi, Slant 6, 440 big block, etc.

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There is a plug on the front of the LH engine cover just above center. Remove it, turn the crank, and you'll see timing marks for both cylinders. The flatside of those cams are not machined well(I got about 5 different clearences before I found the timing marks). As far as where(in specs)to set the gap, the shim options probably won't give you a choice.
 

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The shims will definitely give you the opportunity to keep the valve adjustments on the looser side. Running my TLS frequently at track days & running at prolonged high rpm operation I have done several valve adjustments on my 97' TLS. If the adjustment was just a little tighter than the middle of the clearance range I would swap out that shim with a thinner one to keep it on the edge of the looser end of the clearance range. Works for me.
 

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Also be sure the auto-decom mechanism isn't throwing off your measurments. There's a page in the service manual on how to go about it all, ya might want to download it if you don't have one handy. I don't remeber the specifics (I also checked mine at 17k and haven't checked them since - currently at 47k I think).
 

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Discussion Starter #6
thanks Gerhard, I was making a case for either method in my head, both seemed logical, fortunately I don't have to measure again. Rear cylinders clearances are all right in the middle of the range, front has one out and 2 right at the limit, so looks like I'll only change 3, on the front...pretty easy.

probably easier than hanging the bike and changing the head bearings.


ps, I did download the manual, was just taking a while. I think I'll print out whatever pages I seem to be missing.

:cheers
 
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