Bax,

I just forgot to mention that for better throttle response I am using OS 7L carb instead of 91 FX`s original carb because the acceleration and throttle response is better with 7L. This problem started when I switched to 7L. I have not yet adjusted the mixuture and it is at factory default settings. Could it be a mixture problem?

The reason for which I changed to 7L is this that my 61 SF has lightning fast acceleration and the FX series Carb is not as responsive as 7L. The throat and venturi dias are the same on both carbs.

Thanks