GPZ750 Valve retainer

I was adjusting my valves today and had no clearance on #3 Exhaust valve. Took out the camshaft and bucket and noticed that the shim was not even up to the top of the valve retainer. So putting in a thinner shim would have no effect on the clearance. Can the valve retainer be machined down a few thousandths to give me more clearance and the ability to use a thicker shim? Thanks, Mark

Not the retainer, but the top of the valve stem.

Cutting the valve stem will make the shim sink deeper wouldn't it?

How thick is the shim in question? Unless it's at the minimum thickness, I don't understand how this issue can occur.

BTW, I think you could cut down the top valve spring retainer but I doubt you could get enough out of it to move the shim more than a size or two.

The under side of the bucket has a protrusion that should sit on the shim and keep the retainer from riding on the bucket.
You need to check this first as you may be ok to just fit a thinner shim.
if you are on the thinnest shim size you need to check the installed stem height to see if the stem can be tipped.
If someone has already tipped the valve and maybe took off more than the limit and the bucket IS actually riding on the retainer then yes you could skim a bit off the top of the shim recess wall but you need to know what you are doing.
Either way the valve stem should be sitting higher than the bottom of the shim recess otherwise you are looking at trying a new valve in its place to get the clearance back.

The valve stem was tipped during the course of a valve job last winter. 8,000 miles later there is no clearance at that valve. The bucket is now riding on the valve retainer and not making contact with the shim at all. The shim is setting below the top of the valve retainer. The only way I see to get more clearance and have the bucket ride on a shim, is to shave the top of the valve retainer.

Did they cut the seat too deep?
Steve

Madtrout wrote: The valve stem was tipped during the course of a valve job last winter. 8,000 miles later there is no clearance at that valve. The bucket is now riding on the valve retainer and not making contact with the shim at all. The shim is setting below the top of the valve retainer. The only way I see to get more clearance and have the bucket ride on a shim, is to shave the top of the valve retainer.

You can "shave" some material from the top of the retainer to expose the top of the shim which will allow the bucket to sit on the shim but you need to be sure that the valve stem is protruding above the bottom of the retainer recess and that the shim isn't actually bearing down on the retainer also.

The valve stem is sitting fine. I'll take a few thousandths off the top of the retainer so the shim is clearing enough for the bucket to sit properly. Thanks for all of your feedback. I'll report back when it is done.. Mark

Morning all. Here's the update. I successfully took off a few thousandths from the retainer and now the shim clears the top of the retainer. I used a Dremel tool with a right angle adaptor to get a good level approach to the area. I'm now using a 2.40 shim with room to get smaller if I ever need to. The new cam chain from Z1 comes in today and I'll be attempting to thread the new chain to the old one and peen the link. Wish me luck! Thanks for all of your advice . Mark



Mark