Time for race gas?

[oic0]

Last time I pulled my motor apart and put it together with a cheap gasket set. Before it had ~160psi. Now it makes over 170psi. Think I need race gas to run it like this? it runs great but I don't want to tear up the head with detonation damage. There are a few gas stations in town that sell 100 octane for a kidney or two.

[Polar-Bus]

I run the optional "race" .2mm  head gasket, and I am about 175 psi. I run a 50/50 mix of pump premium and CAM II 110  I'm jetted crisp and my engine runs mint. To get detonation you need higher rpm's and a heavy engine load and generally speaking the KX500 sees neither of those situations !   

[Goat]

There is a thread on race fuel. I'll see if I can find it and post it here for ya.

170 psi is normal for any fresh rebuilt engine. Race fuel isn't necessary unless you are running high compression numbers like 13:1 or higher if I remember correctly.If you're just running stock or slightly larger bore you'd just be wasting money on race fuel. I run the highest octane I can get at the pump which depends on the gas station. Usually ranges between 92 and 94. Sometimes when I'm feelin saucy I'll buy some octane boost but from what I've read it usually only gives you a point or two higher octane rating.

[Polar-Bus]

Goat has a good point. Do I need race fuel ?  "prabably not" But for the minimal hours I use my KX500, the additional detonation protection peace of mind is worth it to me.  Especially where I really tach up the rpm's blasting sustained high speed runs out on the ice in the winter ! 

[awak100]

You can hear a motor detinate.  People sure like buying that expensive gas.  Funny thing is, if you havent up compression, your wasting your money.  OK go ahead put that race gas in it$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$