i have a 87 250r .080 over with a 38 keihin carb intake spacer k&n air filter f&f pipe . at about 1/2 to 3/4 throttle it makes a pinging noise. i need some help.

 

What's your compression?
Either you are lean or have too much compression for the fuel you are running. Or if your fuel is too old.
You should be running at least 92 octane with a stock engine.
ERIC

 

mix in 1 gallon race gas with 4 gallons of 92 octane. that will put you at about 96 octane depending on the race gas. if that doesn't work then mix it stronger or you can retard your ignition timing. i prefer race gas; much more throtle response and a little more power.[img]i/expressions/face-icon-small-happy.gif[/img]