Race Fuel in a 1974 Yamaha RD350

Not sure how familiar anyone here is with 2 strokes…just purchased a 74 RD350 and the engine had been modified for racing:

-cylinder bore
-stage 3 porting
-enlarged reed case
-rebuilt crank
-PVL ignition
-moto carrera expansion chambers

My question is if this bike NEEDS race fuel or if it would be damaged by the 93 octane found at every gas station?

It’s hard to say for sure Ron. It’s possible it will need race fuel, or a 50/50 mix. You won’t know for sure unless you run it on a lower grade fuel and see if it performs. Put in 93 octane, fire it up and go for a zip around the block. If you hear pinging (pre-detonation) then you need to run a higher octane fuel. Do you know what the compression ratio is? Or just the compression itself?

Evan Fell

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