KX500 in S. Colorado... sumo, anyone?

[jlvdo]

Hi everyone,
I used to have a KH500.   Now, just got a 1999 KX500 single.  I'm jazzed .   I'm turning the KX into a sumo for race and track daze.   This set-up oughta' allow me to race at the road race club here in CO, as well as on the sumo circuit as well.   Never had that much track time when I raced the liter bike.
A couple concerns:
1.  Pre-mix.  I know its not rocket science- stock pre-mix ratio is 32:1.   I've some Yamalube R to use right off.   Should I lower the ratio for the track?
2.   Will the motor hold up under stresses of the track?   The ol' 500 triple took me across country(no joke) and held up fine.    I'm no Valentino (hell, I'm not even in the same universe.  I've got nothin' to prove, jus' call me Mr. McGoo), but I like goin' fast as I can.   Any other engine prep for longevity anyone can recommend?   I do have to change the rad fluid to water w/wetter.    I suppose keeping it as stock possible should help.
Thanks for the read and the help!

[hughes]

Welcome,

Yamalube 2-R is the best oil I have ever used. I have ran it for a few years in my 500 with great results. You'll find it is a very clean burning oil. Ratio wise I've always used 32:1 and nothing else. The kx500 engine is the most dependable 2-stroke dirt bike engine you'll find. The question is not that the kx500 engine can hold up under the stress of riding track but can you hold up to the stress 

[blueoval]

Be sure it has good compression, passes the vacuum test, keep the air filter clean, frequent oil changes, and keep up with general maintenance and it will not let you down!

[bluebarite]

Drop your pilot and main main several from stock if you have not already, bike will drastically improve in CO altitude (5.5K). Replace that rear shovel fender with a KX250 92 or 93 rear fender will look a lot better.