1988 Honda cbr tunning
 

i just bought this bike and I cleaned the carbs and tank was running ok after but I can't seem to get the fuel to air ratio right is there a spot to tune? Plz help thanks

Clint Davis

what symptoms are you having?

Many people when they clean the carburetors don't clean them fully. The most often left out part that they don't clean and inspect is the Idle Air mixture screw. It's the funny one on the bottom of the carburetor with a "D" shaped head. That is the one that adjusts the Air Fuel mixture during idle. It's initial opening position is 1.5 turns out from fully closed. That is before performing the Idle Drop procedure. During the procedure, you're turning the idle mixture screw in and out in order to get the highest possible RPM. Then you're turning it in until the RPM drops by 50 RPM. (this is really tough to do because the RPM is usually fluctuating up and down anyway). Naturally you have to have a meter that is able to measure small changes in RPM, your regular tachometer is not really accurate enough for this procedure. Anyway, ultimately you're then supposed to turn the screw out 3/4 of a turn from that position.

I think that you'll probably end up somewhere around 1.75 turns out give or take a bit. I think the most important thing is to ensure that for the most part all the screws are turned out to the same position.