Valve shims question

LMAO

Luc is very correct about the shims with the A marking. If you doubt him, take a micrometer to the A shims and non-A Kaw 29mm shims. Same thickness.

Also, disagree with their characterization of aftermarket shims as poor quality. Note that the ones showing wear have no markings? How would you know if they are factory shims OR aftermarket? I have used both and have not seen many with wear in the hardening and surely can't tell if they are OEM or aftermarket.

This kind of points out how because folks read something on the internet, it all of a sudden becomes gospel. Half the stuff gurus write is questionable... check it out before taking it for granted that because it is written down on a web page, it is correct.

luc wrote:

Redlinecycle is wrong regarding the explanation for the "A" on a shim.
It is not, as they said, to denote a slightly thicker shim installed at the factory but rather is is to identify shims that had a stricter QC standards.
Back in June 21 1973, Kawasaki issued a Service Bulletin (73 Z-13) titled "Z1 tapped replacement" to addres the issue of shims faillure due to a combination of shim and tappet design..
The tappet had an oil hole/navel in the center and the shims were flexing on top of it and fracturing.
To solve the problem tappets were replaced with tappets without oil hole/navel and new shims were put in production with a much stricter QC and all bikes in service were supposed to have both tappets and shims replaced regardless of their warranty status.
Kawasaki called that a "factory directed modification" and allowed 1.5 hour for the job
Those shims were identified with the letter "A" but did not have a new or differernt part #.
After a few years,assuming that all the earlier, non "A" shims woud have been removed from service and inventory, Kawasaki dropped the "A".

Hey Luc, That's some very thorough and esoteric information. Thanks for sharing. You must have worked at a dealership back in the day.

wiredgeorge wrote:

Luc is very correct about the shims with the A marking. If you doubt him, take a micrometer to the A shims and non-A Kaw 29mm shims. Same thickness.

Also, disagree with their characterization of aftermarket shims as poor quality. Note that the ones showing wear have no markings? How would you know if they are factory shims OR aftermarket? I have used both and have not seen many with wear in the hardening and surely can't tell if they are OEM or aftermarket.

This kind of points out how because folks read something on the internet, it all of a sudden becomes gospel. Half the stuff gurus write is questionable... check it out before taking it for granted that because it is written down on a web page, it is correct.

well, dont i feel foolish!!...i am well aware of the pitfalls of believing everything you read on the internet, but at the same time, i thought i was linking to an experienced source for parts and info...
i guess it would be one thing if redline was two guys rebuilding bikes in their basement and had a blog somewhere, but these guys sell alot of bikes and the pics on their website show what appears to be quality resto work....they have a lot of tips and info that i have also seen here
and other sites...i didnt doubt for a minute that they would have correct info on something as elementary and commonly changed as shims....i guess
its all part of the learning curve....sorry guys and gals......keith....thanks to members for corrections on this one....

The idea of sharing and trading shims is a good one. The ZRXOA has an entire shim kit that gets passed around to board members over there and it sems to work out pretty well. The rules for use are pretty simple. Put your name on the list (they have a thread on the board for this), replace what you use from the kit (can be used ones you did not need, new ones, or a check) , then send it on to the next person on the list.

TexasKZ wrote:

The idea of sharing and trading shims is a good one. The ZRXOA has an entire shim kit that gets passed around to board members over there and it sems to work out pretty well. The rules for use are pretty simple. Put your name on the list (they have a thread on the board for this), replace what you use from the kit (can be used ones you did not need, new ones, or a check) , then send it on to the next person on the list.

i still think this idea has legs here....