Re: '41 super 8 stumbles on idle

Posted by Owen_Dyneto On 2012/3/19 17:51:07

Sounds like you have a Viton-tipped needle and they are problematic with 10% EtOH fuel so as you suggest, I'd replace it with a steel needle/brass seat (the most commonly found arrangement). Needle/seat sets are not usually sold individually, only as part of a rebuild kit. Best kits I know of are from Daytona Parts in FL.

3.5 psi fuel pressure sounds just fine, but why would you ever run the electric pump in tandem with the mechanical? In a mechanical pump the pressure is created by the spring that provides the upwards force onthe diaphragm - perhaps you should check your fuel pressure more thoroughly.

Someone more familiar with your carb should comment on setting the float level; sometimes you set it dry, inverted with a measured gap between two surfaces, and in other carbs you actually measure the fuel level. Best to re-read your instructions to be sure you got the right measurement.