Valve Shim Question

Run the valve adjustment on the KZ Saturday. Pulled out a shim that was marked 245A. I'd never seen one with a letter in the number designation. Does anyone one know if the "A" has some special meaning I should be aware of before ordering a #240 shim.

Thanks in advance for your expertise.

The number is all that matters.

jdburke wrote:

Run the valve adjustment on the KZ Saturday. Pulled out a shim that was marked 245A. I'd never seen one with a letter in the number designation. Does anyone one know if the "A" has some special meaning I should be aware of before ordering a #240 shim.

Thanks in advance for your expertise.

The number is the thickness in millimeters: 245 is 2.45mm which corresponds to 0.973" if I did the math right. On my engine, the available shim sizes run from about 220 to 320 as I recall.

To answer your question, the A has no particular meaning. You pulled out a 2.45mm shim whether there was an A or not. I usually use a digital caliper to confirm shim thicknesses as they can sometimes be tough to read.

Thanks for the replies. For some reason the other 4 shims came out fairly easy, and this particular one was a pain in the needle nose. Thought I'd check just in case.

Thanks Again,

Shims stick in the bucket because of hydrostatic tension... there is oil between the shim and bucket that sometimes makes them a chore to remove. Not unusual... if you pull out 5 shims, at least ONE bucket won't want to swivel easily and the shim will feel like it is glued in. A dental pick and pencil type magnet are useful for removing them.

I made a chart, shim number vs thickness in thousanths. That way I can tell what shim I have. I always use a caliper to check thickness as there are slight variations in the shim thickness. However, I never seem to have the exact one I need as that particular shim is usually needed on two valves......chris3

coppertales wrote:

I made a chart, shim number vs thickness in thousanths. That way I can tell what shim I have. I always use a caliper to check thickness as there are slight variations in the shim thickness. However, I never seem to have the exact one I need as that particular shim is usually needed on two valves......chris3

Murphy's Law. Just be grateful your bike doesn't use the 32mm shims like the twins that haven't been made in decades and nobody can get.

I was very lucky. I pulled out 4 shims and was able to swap 3 around and only dipped into the shim stash for 1. Now if I can just get air bleed on the pilot circuit of #2 carb to open up without have to pull the carbs off....

If you need to buy shims at the dealer then measure them no matter what is marked on them. I had to return a shim marked 240 because it was a 245. My clearance hadn't changed after the swap and I couldn't figure out why...the service guy said he never saw a mis marked shim in his career.

OKC_Kent wrote:

If you need to buy shims at the dealer then measure them no matter what is marked on them. I had to return a shim marked 240 because it was a 245. My clearance hadn't changed after the swap and I couldn't figure out why...the service guy said he never saw a mis marked shim in his career.

I never heard of that either. I guess you just can't get good Chinese prisoner labor these days....:laugh:

I have seen quite a few shims that measure in between though. Say, instead of 245, it measured out as 248. Measured and remeasured and have found this a few times which can mess you up. Just a hair to big or small and if you go the next one, it puts you outside of recommended limit. Doesn't really hurt anything but more work is involves to get it right sometimes.