Valve shim advice

Hi again!

I recently got a non-running '84 GPz 550 running. So far, so good.
However tonight I was measuring the valve clearances, and they're tight.
I followed the Clymer measurment procedure (manually spinning the engine until the cam lobe points were completely opposite the buckets and these are my results (all measurements in mm)

CLYMER SPEC: Intake: 0.10-0.20, Exhaust: 0.15-0.25

1e: 0.14 2e: 0.15 3e: 0.10 4e: 0.15
1i: 0.07 2i: 0.04 3i: <0.04 4i: 0.10

I took the cams out and measured the shims that are already in there with a cheap set of digital calipers (probably not the most accurate). I measured each several times, zeroing out the caliper against itself before each measurement and spinning the shim between each measurement. Results:

1e: 2.47 2e: 2.53 3e: 2.48 4e: 2.49
1i: 2.60 2i: 2.53 3i: 2.50 4i: 2.50

What size shims should I be putting in each valve? Do I want to shoot for the middle of the allowable spec, or the loose end, as they will tighten up with wear?

They should be numbered on the undersides.
Steve

I looked closely on each and was not able to see any numbers.

Middle of the spec is what you want to shoot for. Too large of a gap will cause more noise as the valves hit the seats. This noise is the result of higher impact on the seat. Too small of a gap and you will have to do it again sooner.

You will need a good caliper or micrometer to measure your shims if they are not marked.

The FSM will tell you what size shim to use based on what is in there now and the measured gap. But to use that chart correctly you should follow the manual's measuring procedure. It is not as simple as the Clymer method, but is likely more precise. In my experience, the FSM method produced more repeatable results.

The valve train warning in my signature has notes on the FSM method, and if you follow the links, you can download several FSM's with supplements for the Zx550. The warning page also explains why you should not re-install the cover without releasing the tensioner. There are also better images for setting the cam timing.

loudhvx, thanks so much (again). You are an amazing wealth of information on these bikes. I will reinstall the cams and measure as per the FSM, then go down to my Kawi dealer, hopefully they will sell me some shims individually.

We have had some good debates around here about how to position the cams for the best measurements. I'm of the belief that the Clymers manual instruction on how to position the cams is incorrect but passable. It will result in the lash measurement being larger than would be the case if using the method from the factory Kawasaki manual is all. No big crisis but I'd target the middle to lower end of the spec range to hedge your bet, not to the high end, if you chose to use the measurements you have. Or reinstall the cams and try again. I'd at least swap in the new shims before remeasuring. That's just me though.

Valve clearance checking is not rocket science. The Factory Manuals a chart, showing the shim needed based on the shim you have, and the gap measured. Good tools is again highly recommended to gat repeatable data. Checking them again after changing the shims is recommended. When in doubt, a noisy valve is a happy valve.

Don't go by the "feel" method in deciding on the clearance of the feeler gauge. For example, if a .004" (.010 mm) goes in, but a .005" (,127 mm) doesn't, then call it a .004".

Looking at the numbers you have provided, and taking into account your caliper seems to be measuring under by 2 and shims only available in increments of 5 you will need to replace as follow,
INLET SIDE in1, 250, in2, 245, in3, 240, in4, 245.

EXHAUST SIDE ex1, 235, ex2, 245, ex3, 230, ex4, 240.

You may also find these possibly may need doing again if you are using a cheap caliper, i use a Mitutoyo micrometer 0.001mm to 25mm to measure shims that are unmarked.

Feel free to correct these calculations if i have made mistakes please.

Thanks for the advice. I have a real micrometer coming in the mail, I don't trust my caliper measurements.

Hi again,

Just wanted to update everyone - I finally got my micrometer in from amazon which allowed my to precisely measure each of the shims that were in it. Good thing I did that, because a few of my digital caliper measurements that were inaccurate enough that I would've rounded them down when I should've rounded up.

Anyways, I ordered shims, put them in and now my clearances all check out. Thanks again for all your help!

Good thing about a micrometer is that it measures the shim centre, where it wears, rather than the edges as with a vernier caliper. Most shims have is some measurable wear in them when the numbers are worn off,