for an old 1975 honda cb500twith original valves and seats i was told if i dont use the correct octane i will stuff the valves and seats because they arent hardened thas why i sold my 72 trumpy 15 years ago. any feedback gratefully accepted
mm12345,
May 9, 3:44pm
If the valves / seats aren't hardened, then the problem is from lead-free fuel.I'd use premium fuel with additive (valvemaster) or (leaded) avgas if you can get it. The additive won't totally prevent valve seat recession - but it does reduce it.
vat69,
May 9, 6:50pm
by premium do you mean 95 or 96!the motor seems to spit misfire and splutter on it by runs ok with 91
bellky,
May 9, 6:56pm
Just use 91 then.
moosie_21,
May 10, 12:26am
HOW DO PEOPLE KEEP THINKING 96 STILL EXISTS!!!!!
saki,
May 10, 12:43am
You sold an old trumpy just because of that.
dave653,
May 10, 5:23pm
Reduce the octane. quadruple the price!
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