Leaded or Unleaded???

[Scott400EX]

Can i run leaded race gas in my 400 with stock head and mods below or will i need to do anything to the valves?

[YZROOSTINYA]

yes you can but watch your octane. if you go too high you will lose power

lead was initially put in gas to raise the octane and soften the imapct between the valve seats and cylinder walls. but after time it was a environmenatl hazard.

mix 1 gallon of 105 octane to 4 gallons 93 and that is more than enough.

you really dont even need to run race gas. although its a good idea on hot race days

[Colby@C&DRacing]

Yes you can run leaded fuel. Almost all race fuel is leaded. It is a top end lube. Just don't run too high of an octane.

[Scott400EX]

so what would be good? I can get 103, 108, 110, 114, 117 VP race fuel at my local bike shop.
or i can get 100, 108, 110, and 114 at virginia international raceway 10 miles away.

what would you recomend?
unleaded 93 mixed 50/50 with leaded 100?

[YZROOSTINYA]

run the 100 straight or mix it 50/50 you really dont need 100 but it isnt high enough to hurt.

some people put 108 in a stock motor thats what i wasd trying to say.

the ideal fuel would be in the 95-96 range so either mix 1 gal 108 to 4 93 or 50/50 100/93

[Scott400EX]

OK i got 5 gallons of VP C12 leaded 108. So if i mix that with 93

if i mix 2 gal 108 and 3 gal 93 thats 99 that should be about perfect til i run out of 108 !!:D

[KandK952]

i thought vp c12 was 110 octane but you may be right. that is what i use sometimes. mix half of that with 94 octane pump gas. always ran good for me.

[Scott400EX]

awesome does it make any difference in power? Im guessing its not enough to notice

[YZROOSTINYA]

it will not make ANYMORE power but let your engine run at its full potential without detonation. the lead also dissapates heat faster which helps it run slightly cooler. what you might notice is it will be a little snappier. if you look at a dyno it also burns cleaner and the graqphs tend to be smoother. like pump gas will be 33.4 then 33.7 then 33.1.... the race will see 33.4, 33.4, 33.4 all throughout you got me. it runs the same everytime