You are right about the old air cooled bikes, just showing my age again! d**n
I looked in my old YZ490 manual and the recommended 24:1 d**n that's almost straight oil! No wonder we fouled plugs!
When I bought the bike is was told to run 32:1, so that's what I have been using.
I used an octane booster in my YZ490 due to the high compression ratio and the detonation problem. Explain why you use the race gas mix.
Thanks?
Alan