I recently modified my '09 CRF230F: 132 main 45 pilot 921 power-up needle 1.5 turns on mixture screw Air box snorkel removed FMF Power Core 4 NoToil air cleaner The bike runs great, I can't find any flat spots etc in the rpm band. My question: If the bike is at idle and you crank the throttle quickly open to mid-full it stalls, or doesn't fire. This only happens off idle, once the engine revs up slightly it takes off and runs fine. I noticed my '05 230F does the same thing. If I turn the idle up to ~1800rpm it helps, but doesn't clear it completely. I have adjusted the fuel screw, tried different needle clip positions and it doesn't change. Is this normal due to the mechanical carb versus a CV carb? I never run into the problem when I'm riding. I was just curious if there is a fix or if that's just how it's supposed to be.
Without a pump, they can do that. If the carb is small for the motor size and set very rich, it reduces it. The cv carb was designed to prevent that and allow the mixture to be more stable without large changes in the air/fuel ratio. Pumper carbs seem to be the best of both worlds, great throttle response... Then you can set the jets on the lean side to get good mpg and keep the throttle response.
That's what I thought. Thank you for your input. I just wanted to confirm that it was normal for this type of carb.
