Thickest valve shim?

[Feo]

What's the thickest valve shim you've found in a K engine?

Checked my valves in conjunction with a timing chain rehab, all my exhausts were at .20mm. A bit tight, no?

I've got the valve shim tools coming from Ken Lively, but since I had it down, I pulled the exhaust cam so I could start tracking down shims. None were marked, so I pulled out the old micrometer and started measuring. It's inches, so read accordingly.

#1 cylinder-  .112 inches

#2 cylinder-  .110 inches

#3 cylinder-   .132 inches

So, pick up pencil, do some figuring. 2.8448, 2.794, 3.3528.

Ummm, what?

3.35mm? So I'd need a 3.25mm shim to get back on the loose side, right?

The largest shim I can find on the innerwebs is 3.10mm (I was thinking 3.0mm was where they stopped).

So a 3.10mm shim would give me about .45mm clearance, which works out to (rounded up) 18 thousands.

Bit excessive, no?

Two different micrometers, a calculator, Google convert, a storm door install (don't let Pansy kick your storm door LOL), I finally had a different idea.

Back to it after supper.

[Martin]

Apparently some model Kawasakis & Yamahas use the same diameter shims. Find a local dealer and take an old one in it would worth checking to see if they come in thicker sizes. Some internet shims are apparently slightly to big.
Regards Martin.

[TimTyler]

You'll need thinner shims to create a larger gap if you have tight valve specs.

2.00mm is the thinnest available.

[Bill]

I think you want thinner shims as the cam operates directly on the valve.  Thicker ones would make the valve clearance tighter.  Never done it so I am not 100 % sure  :dunno2:

[TimTyler]

You want the exhaust valve gaps to be between 0.25mm and 0.30mm, but closer to 0.30mm.

You currently have a 2.85mm shim in #1, 2.80mm in #2, and a 3.35mm in #3.

If all your exhausts valve gaps are at 0.20mm then my math says you should put 2.75mm shim in cylinders 1, a 2.70mm in #2, and a 3.25mm shim in cylinder #3.

Please confirm with someone smarter than me though!

[Feo]

I've got 2.85, 2.8 and 3.35 shims, respectively.

To get to .30mm clearance I'd need 2.75, 2.7 and 3.25, respectively.

No 3.25 shims available, from what I can find. 3.20 shim would give .35mm (.014 inches) clearance.

But, there's more than one way to skin a 'possum (and don't ask what goes in my chili if you're hungry).

[TimTyler]

I've got 2.85, 2.8 and 3.35 shims, respectively.

Yeah - That's what I said.    :nono

(Full disclosure: Okay, not really. I went back and edited my previous post  :neener: )

[Feo]

Is an exhaust clearance of .013-.014 workable?

And has anyone ever swapped cam buckets between bores? (On purpose, not alcohol inspired modification LOL)

Because there's definitely differences in height (thickness) between buckets.

[Laitch]

Much here depends on the accuracy of the initial gap measurement and the accuracy of your micrometer. Verification of measurements with a different measuring tool might be appropriate now. Shims greater than 3.00mm aren't part of a K75 kit.

Is this the bike with 70K, Feo?

[Feo]

This one says 65k (almost 66k) on the odometer. It's pretty new to me, so it's a maintenance journey of discovery.  :riding:

I checked the shim thickness with two different micrometers and a dial caliper.

.1315 to .1320

I checked the clearance with a metric feeler gauge but basically a go/no go check. The .20mm would go, the .25mm wouldn't. The feeler gauges felt the same, friction-wise on all 3. All intakes were .15mm, and felt equally consistent.

I'm gonna do some more measuring in the morning with my morning coffee. I pulled a new 2.60 Kawasaki shim out of my parts stash and I'm gonna compare bucket to bucket with that shim. And check the OD on the buckets as well as seeing if there's any cam or barrel shape to them.

[Laitch]

. . . two different micrometers and a dial caliper.

They are what you refer to as "the old micrometer." It's clear to me now.

[The Mighty Gryphon]

A long, long time ago I was a test tech for a company that made servo valves for controlling jets and missles.  The torque motors on the valves used shims to adjust the center point of the motor.

Anyway, one of the things we did was to grind the the shims down to make fine adjustments in thickness.  If you cannot find the shims you need what I would suggest is to get a medium fine carborundum sharpening stone about 1 1/2" x 5",  some oil, and a sharpie pen. 

Mark the shim on one side with the sharpie and gently grind that side on the stone in a figure eight pattern until the ink is ground off.  Clean the oil off, measure, mark and grind until you hit the measurement you need.  I would think that about a half hour or less would do it.  When you install the shim, put the ground side facing the valve stem, not the cam.  By hand grinding you will not disturb the heat treating of the shim. 

[Feo]

Well, after a good night's sleep, I woke to realize I'm a dumbass.

That can't read a micrometer right.

  :bang-head:

.1032, not .132

By the time I pulled out the caliper, my mind was already set on having a mess in the making, so it was informing my eyes, not the other way around.

Proper shims in, cam and timing chain installed, now, no more home improvement projects until I get the bike back together.