This is a '73 Challenger 180 with a Lycoming O-360 A4A.
When I advance the throttle the engine stumbles at 1200RPM and then immediately resumes normal operation. This does not occur as I reduce the throttle. It also does not occur if I lean out the mixture about an inch. I've encountered no issues at high power settings.
I know that 1200rpm is about where the carb switches off of the idle setting. Since it only happens when advancing the throttle, it makes me think the accelerator pump is pushing the mixture over-rich. I see 15gph on climbout, which I think is about right.
Is it possible that my carb is too rich at lower power when it comes off the idle setting, but then is correct at full power? What could cause this?
Alternately, could my accelerator pump be delivering too much fuel?
Are there any other possible causes I'm missing?
When I advance the throttle the engine stumbles at 1200RPM and then immediately resumes normal operation. This does not occur as I reduce the throttle. It also does not occur if I lean out the mixture about an inch. I've encountered no issues at high power settings.
I know that 1200rpm is about where the carb switches off of the idle setting. Since it only happens when advancing the throttle, it makes me think the accelerator pump is pushing the mixture over-rich. I see 15gph on climbout, which I think is about right.
Is it possible that my carb is too rich at lower power when it comes off the idle setting, but then is correct at full power? What could cause this?
Alternately, could my accelerator pump be delivering too much fuel?
Are there any other possible causes I'm missing?
