04 Kuibblewhite valve issues

[TrlCutter]

This one has me stumped. I installed the Kibblewhite valves and springs along with the Hot Cams in an O4. The seats were touched up by a local shop (Larry McBride SpiderMan top fuel drag bike). Every race (2 hour hare scramble) the intake valve will loose .002- .003". I have re shimmed them twice for a total change of .006" on the right intake and .005 on the left intake

After last weeks race both clearances are down to less than .003" again. I did this same thing to another 04 I worked on with great results. Any suggestions.

[rodwhitejr]

I did just exactly the same steps in my 04 last week....rode it only once so far and did reshim one intake, but it was on the tight end of spec when I put it all together. Sure hope someone has an answer for you, since i could potentially be in the same boat. Hopefully yours will settle in soon....seems like alot of $$ to spend if nothing was gained

[MXER43]

This one has me stumped. I installed the Kibblewhite valves and springs along with the Hot Cams in an O4. The seats were touched up by a local shop (Larry McBride SpiderMan top fuel drag bike). Every race (2 hour hare scramble) the intake valve will loose .002- .003". I have re shimmed them twice for a total change of .006" on the right intake and .005 on the left intake

After last weeks race both clearances are down to less than .003" again. I did this same thing to another 04 I worked on with great results. Any suggestions.

What shape were the guides in when you installed the new valves and springs? How much did the guy who cut you sets cut down? He could have gone too deep and changed the installed height too much causing a weak spring at condition. I have seen stainless valves wear out fast with the wrong spring pressure or worn guides. If you have never replaced the guides, it's a pretty good bet that they are out of spec.

[NoFearOakley48]

i put kibblewhite valves and spring kit in my kx250f (04) and they moved once when i broke the the bike in and havnt moved yet

[TrlCutter]

I was told the guides were fine, they were installed when the last set were installed in this bike. This is the third set of valves in this bike. First year no problems, adjusted a couple of times in a year, the next set were installed (all stock) and that is when this started. after a few hours they would be out of specs (tight). I had to re-shim them several times last year. So I went with the Kibblewhites with the same results, with the intakes. I am going to take the head off and check and see if its the valves or the seats. Not ina ahurry though, picking up a new RM-250 saturday. I don't think I will have a valve problem with that.................LOL