valve clearance math check

[SkyfangR]

need a little assistance checking my maths

just checked my valve clearances, and they're all well within spec (both right sides @.08mm, left front @.06mm) except the left rear valve (intake i think)
it's got no clearance.

the current shim in that spot is a 2.75 (i measured with my micrometer, the middle number is worn off. i can only see 2.*5)

i need to go SMALLER on shim size to open up some clearance, yes? so i would want a 2.70 or a 2.65?

[Rich82GS750TZ]

I think you’re right, you should always need to go smaller and smaller as valve clearance lessens with miles. Steve has developed a spreadsheet to take the guesswork out of it. It would be good for you to have, if you’re even mildly handy with Microsoft Excel. He emailed it to me even though I don’t need it (the 16 Valve engines don’t use shims). If you like, give me your email address and I’ll forward it to you.

[Rijko]

need a little assistance checking my maths

just checked my valve clearances, and they're all well within spec (both right sides @.08mm, left front @.06mm) except the left rear valve (intake i think)
it's got no clearance.

the current shim in that spot is a 2.75 (i measured with my micrometer, the middle number is worn off. i can only see 2.*5)

i need to go SMALLER on shim size to open up some clearance, yes? so i would want a 2.70 or a 2.65?

No clearance = smaller shim, definitely.

So you have a 2.75 and NO clearance, and want approx. .08 mm of play.
Shims come in increments of .05. (exception are the 'X' shims but those are rare)

So a 2.70 would give you less gap than .05mm.
A 2.65 or 2.60 might do the job.

First thing i would do is write down the size of what you have, the other 3 shims.
You will need to buy a shim : swapping is not an option because you would replace
another shim with one at least 2 sizes (0.10mm) bigger.

If you have a shim smaller than 2.75 you can swap it out to be able to take exact
measurements.
Swap them, do not forget.
A cam lobe meeting the cam follower without a shim in there is not good.

[Rijko]

btw, a 2nd hand original or NOS shim is best :
most aftermarket shims are cut with straight sides that can be hard to mount.
Original ones have a slight edge that makes it slide in way easier.

Most Suzuki dealers i know will swap the shim for free or for a small fee.
And while talking to them they usually say i have not used them forever.
And sometimes will sell them cheap.
Over the years i collected a nice stash like that

[Nessism]

i need to go SMALLER on shim size to open up some clearance, yes? so i would want a 2.70 or a 2.65?

Buy both, and more. Take a full inventory and buy enough shims for your next couple adjustments. Most of the time you can shuffle shims to some extent so you should only need to buy half dozen extra or so. Shims cost about $5/each so it's now a heavy commitment. And while you're at it get a couple valve cover gaskets too (OEM type.) Good deals on gaskets can be found on ebay. Stock up and save.

[SkyfangR]

thanks all. i bought a 2.70 and a 2.65 and a valve cover gasket on ebay. just gotta wait till they get delivered, and finish the swap. will buy more shims when i get paid again

[phydeauxmutt]

Be sure to check the shim DIAMETER. Kawasaki and some Yamaha engines use a 29.0, Suzuki uses 29.5. It's hard to tell the difference by just looking.

[SkyfangR]

found a local guy who had the 2.70 and 2.65 size shims, went and picked them up. the 2.70 is MARKED 2.70, but my micrometer says its 2.74 thick
the marked 2.65 was actually 2.67, which turned out to be perfect. i dropped the 2.65 in and checked clearance, it's at .07mm now.
went out for a victory lap, had fun

[angrypants]

Yeah virtually all my shims are not exactly the size written on them