Posted by kEN (32.102.154.9) on April 11, 2001 at 18:50:04:
In Reply to: Re: Engine breathing ability posted by Chris W. on April 11, 2001 at 05:09:04:
You are right, if I interpert what you said that air velocity is lower with larger carb and would tend to draw less fuel. Yes on the basis of (just a carb change). What happens is that the air-fuel ratio goes leaner when changing to a larger unit, do to the air flow speed reduction. Carb not meant for the size of the engine very often. If test equipment were used to see this, I'm sure it would be sugestive of the need to increase main jet size to compensate for the reduced airflow. Therefore to bring the air-fuel ratio back to match the size of the carb. The milage gain would be cancelled and may even be worse.
Said another simpler way, going to a larger carb to effect better fuel milage appears to be a solution but in reality the smaller carb needs to be rejetted then the fuel milage should improve along with throttle response.
Thanks for reponding as these subjects are deeper than meets the eye so to speak.
Can I sell this to you today?
Best to you.
Ken