CRAP! Need Help, messed up a valve job...

By the way, Kawasaki service limit on valve stem grinding is .012" I would bet that you have exceeded that by a bit.

PLUMMEN wrote:

another problem with sinking your valves is the compression will be down just a little and youre also stuck if you ever want to put new valves in that motor down the road

+1, that's what I was thinking. I had good luck on ebay finding new valves for about $12 each for my old 750. I think the seller was Rusty Riders LLC or some name like that.

If you do make shims you will have to surface harden them the way Kawi does or they will wear pretty quickly.

There may be a reason that the shims don't go any larger than 3.20 for the 650?

Well grinding is not an option, I don't have that equipemnt. I do not believe that it is necessary. Surface grinding would be a production method, all be it grinding would produce much better surface finish and better parrallel tolerences, I think a well turned part can be sufficient. I can hold .0001" on a part like this, grinding is more like .00005". I have found some other cases online where people have made shims in similar applications. I need to look closely at the valves I have. I know some are burned but between the heads I have taken apart this winter I might be able to put a set together in good enough condition to make work. And the do this all over again. Guess I need to look at my options and make a decision, the snow is melting fast around here.

otakar wrote:

By the way, Kawasaki service limit on valve stem grinding is .012" I would bet that you have exceeded that by a bit.

Not a problem. Do it all the time putting race heads together.

Tyler wrote:

Well grinding is not an option, I don't have that equipemnt. I do not believe that it is necessary. Surface grinding would be a production method, all be it grinding would produce much better surface finish and better parrallel tolerences, I think a well turned part can be sufficient. I can hold .0001" on a part like this, grinding is more like .00005". I have found some other cases online where people have made shims in similar applications. I need to look closely at the valves I have. I know some are burned but between the heads I have taken apart this winter I might be able to put a set together in good enough condition to make work. And the do this all over again. Guess I need to look at my options and make a decision, the snow is melting fast around here.

The problem with making shims is that the next time you need to make an adjustment (new valve jobs almost always seat and tighten up the clearance), you would have to make some more shims.

Best bet is to get new valves. Did you tip them yourself, or have a shop do it? You would want to be careful with that on the new valves.

Jay

Well this problem is now resolved. I measured again and I need shims from 2.90 to 3.35 to get my clearences correct. I opted to instead look at the other valves I had. So I cleaned up 16 valves and measured the stem diameters and checked them for straightness. A few were burns, on was bent, but I put togethger a full set in good condition and started lapping them to the seats with good results. So I should be OK now. I was just one of those situations where the result was sooo close, but too far away... I still don't know why the chart values in the manual were wrong. Oh well live and learn I guess.

If this were an old clunker I would have just made shims, but I would hate to ruin those shiny new pistons.

Thanks everyone for our input.

Well after 6 hours I have another set of valves installed and I can shim these. I was just trying to avoid doing everything over again, you know how that is... I need to get the blue off my hands and go to bed.

Z1 sells shims but is there an exchange anyone on this site knows of. I have quite a few shims, so if anyone is up for trading let me know.