Speed Carb Question

[Bison]

I've been reading that the "authentic" speed carb has a petcock attached to the carb itself. Evidently the other ones that are so popular (red air filter cover) that have asian writing on them are just NT carbs with bigger jets (or something to that effect).

I have one of those... the one with the asian writing on it... sans petcock. Would I see a benefit going to a "real" speed carb at all? I read something about the throttle body being different....

only if it allows more air and fuel to enter the engine and is jetted properly.

 

[DAMIEN1307]

you need to change to the correct jet size to stop the four stroking. I think you need to go to a smaller jet size. have you done a chop {turn of the engine off after traveling long enough as fast as you and long enough to be sure the engine is as hot as it will be} then leave the engine too cool, then take out the spark plug and check the color. black - to rich, gray - great, clear with oil too lean.

only if it allows more air and fuel to enter the engine and is jetted properly.

The Bo Phang carb has jets that are almost as big on the threaded bottom as the top of the jet.

You need to look at the posting date of who your replying to as to when it was posted...This was posted over a year ago on Jul 9, 2022 He solved his problem long ago.

 

[DAMIEN1307]

Thank you

You are welcome.

 

[ImpulseRocket]

BoFeng jets are keihin 99101-124 jets. If that helps. I am a big fan of genuine Keihin jets over cheap kits. They cost more, but I am also getting a jet that I know for sure is the right size for the jet number stamped on it. Cheap jets don't always tend to do that.