Top End Noise

[250xthunder]

So I rebuilt the top end in my 91' 250x, I had to throw a 05' 300ex head on it when all was said and done. Anyway I got everything put back together and it fired right up. The only problem is that there is a real loud rattling noise that sounds like it's coming off of the valves. Lay on the throttle and the noise gets high pitched and faster. Do I just need to adjust my valves better or what could this possibly be???? Oil is getting up there and the wheeler runs great but the noise is really worrying me. Any suggestions would be appreciated. Thanks

[dirtdawg]

if you have a skid plate it may be rattling around. i had a problem like that before. just a little reminder. your valves probably need a little attention. recheck the clearances and you should be good. should be .004 inches clearance, intake and exhaust.

[250xthunder]

Well That's what I've got them set at but man is it loud. oh well, guess i'll find out if its serious or not eventually.

[dirtdawg]

well, i did my valves before and it did that but the feeler gauge needs drag on it in between the valves and rocker arms. it will run really hot if they are too tight and they are noisier the looser they are.