Valve Shim Troubles

I got the top end assembled on my 1261 project and after paying an extra $100 for bench shimming, most of the clearances are out. I have 0 - .002" clearance on 7 of 8 valves. I removed the cams to swap shims to get things into spec (remember these are shim under bucket, 13mm shims) and now I realize that nearly all of the shims installed are on the very low end already. I don't think they make shims small enough to get several into spec.

What is the smallest shim available in 13mm diameter? I have only seen as small as 2.007mm (.079") through Kaw and I need a .075" on one. The Web cams call for a .006" clearance, btw.

I think what happened is the shop messed up, but I'll wait to hear back from them before I mention their name:angry:

I'm afraid the valve stems need ground, but that means pulling off the head and disassembling the valves. What a mess!!

Any suggestions on small shims or other tricks / tips??
Thanks

Post edited by: 79MKII, at: 2007/08/13 22:35

Be careful when doing this. If the head has had numorus valve jobs, or this shop sunk the valves a little too deep, and you tip the valves, you could get in a situation where a thin shim will sit down in the retainer too far causing the bucket to sit on top of thr retainer, not touching the shim.

You could have a disaster if you start it up like that.

This is one of the most common problems people run into when doing valve jobs on these KZ heads.

Jay

IMO, let the shop that did the work straighten it out. Last thing you want to do is start grinding on your valve stems or anything else. Reason is exactly what Jay described.

Don't touch anything. Pull the head off and ship it back to them. Ask them to pay for shipping.

JMO

Larry C

Thanks Jay and Larry - very good advice. The shop usually gets right back to me, but I haven't heard back from them yet...how funny.

I plan to measure the stem to retainer height tonight. By the way, I found someone willing to supply shims in custom sizes. The main question I have is about the hardness. Do the 13mm shims also require hardening? I'm not 100% sure on that because the cam doesn't contact the shim directly as it would with the 29mm shim.

Yes all shims have to be hardend, if not the will mushroom, also they must not be too hard or they will wear the top of the valve or the bottom of the bucket

Try to find all the min and max spec's u can so when u measure everything and talk to your machanic u have all the data very clear in front of u.he may not hvae had all the proper spec's in a kz motor and did what he thought was right.all the data is available.if u need any #'s let us know and we will help u dig them up.i'm sure i have them on file if u need them.

a #200 shim (2mm) is as thin as they come. I had the same thing happen on my 1982 GPZ1100 which was less than a year old. The incompetents ground the valves and seats so much during a valve job a 200 shim was still too thick, so grinding the valve stems was needed. What a mess. The next valve job I had done my a more trusted shop told me I'd have to swap 2-3 sizes down on the shims after their valve job and that's exactly how it was.

OK - I just talked to the shop owner and he has asked that I return the head to be repaired at no cost to me. He explained that since the valves are larger than stock, they had to be seated in pretty deeply to allow valve to valve clearance. This is why the shims are on the small end of the charts. He said he will "tip" to valves and make sure that everything is correct, including the shim/retainer relationship.

He also said that the guy that shimmed it for him should have told him it was so close to making proper specs. He apologized several times and appears very willing to make things right.

He also mentioned that he has seen the valve clearance change many times on the KZ's after they have been bench shimmed and then torqued for final assembly. That part didn't surprise me, but not having small enough shims to correct it is where the problem is. I'll keep you updated...

thats good news, at least the guy is willing to make it right, you dont find that very often;)

79MKII wrote:

OK - I just talked to the shop owner and he has asked that I return the head to be repaired at no cost to me. He explained that since the valves are larger than stock, they had to be seated in pretty deeply to allow valve to valve clearance. This is why the shims are on the small end of the charts. He said he will "tip" to valves and make sure that everything is correct, including the shim/retainer relationship.

He also said that the guy that shimmed it for him should have told him it was so close to making proper specs. He apologized several times and appears very willing to make things right.

He also mentioned that he has seen the valve clearance change many times on the KZ's after they have been bench shimmed and then torqued for final assembly. That part didn't surprise me, but not having small enough shims to correct it is where the problem is. I'll keep you updated...

See..it looks like it's going to all work out for you. Glad to hear that. The guy you spoke to on the phone was straight with you.

FWIW - IMO - paying someone to bench shim is a waste of money. Stem heights are always part of any valve job. Checking that they are in adjustable range is not something you pay extra for [if you know what I mean]Look at a Kawasaki OEM KZ service manual. It will give you stem heights and shim ranges.

Jay sells valve stem height guages and they are not expensive. Might be good for you to have around since you're into building motors.

larrycavan wrote:

FWIW - IMO - paying someone to bench shim is a waste of money. Stem heights are always part of any valve job. Checking that they are in adjustable range is not something you pay extra for [if you know what I mean]Look at a Kawasaki OEM KZ service manual. It will give you stem heights and shim ranges.

Jay sells valve stem height guages and they are not expensive. Might be good for you to have around since you're into building motors.

I hadn't thought of that, and that's exactly why I paid for the bench shimming. I was afraid it would be so far out of spec that the valves would need reworked and I didn't want to go through that. I guess as it worked out, I ended up paying for the bench shimming AND have to take it back apart anyway! Oh well, as long as it ends up done right and doesn't cost me any extra. The shop owner's reaction meant a lot, to tell you the truth. Mistakes happen to everyone, and the way they are handled makes all the differenct to me.

Thanks for all of the help everyone.

u said u have larger valves in the head.it is imperative that u have .200" clearance between the valves at the seat.if u dont u will not be able to degree large lift/duration cams to spec. mine were set at .175 and i had issues.