Okay engine gods and goddesses. Just installed a freshly overhauled MA-4-5 carb from Chief Aircraft. Standard O-360 with a Sensenich GA prop, and E-Mag/P-Mag combo. Advanced Flight Systems digital tach so I assume the tach is accurate.
Adjusted the idle RPM to about 740. Seemed to run smoother there than 650-700. Next I worked on the idle mixture screw, working to get it to give the 30-50 RPM rise when going to cutoff at shut down.
I don't know why but I seem to be having a heck of a time getting all of the parameters to come together and work properly. Currently it runs just a little rough at idle (but smooth at or above 1,000 RPMs) until it warms up (5-7 minutes). Takeoff, cruise, and post flight it runs great (including at idle). But at shutdown, I see about 10 RPM gain (too lean?) but going to cutoff will not always shutdown the engine (too rich?). It will just barely run at cutoff, but will keep stumbling until I shut off the ignition switches.
Seems like this should be a simple process (it was with the old carb) but this one is giving me fits. Any recommendations?
I have checked the timing on the E-Mag and P-Mag and they are good. Also checked for any obvious leaks or visual signs of issues. Compressions were all mid 70s.
Adjusted the idle RPM to about 740. Seemed to run smoother there than 650-700. Next I worked on the idle mixture screw, working to get it to give the 30-50 RPM rise when going to cutoff at shut down.
I don't know why but I seem to be having a heck of a time getting all of the parameters to come together and work properly. Currently it runs just a little rough at idle (but smooth at or above 1,000 RPMs) until it warms up (5-7 minutes). Takeoff, cruise, and post flight it runs great (including at idle). But at shutdown, I see about 10 RPM gain (too lean?) but going to cutoff will not always shutdown the engine (too rich?). It will just barely run at cutoff, but will keep stumbling until I shut off the ignition switches.
Seems like this should be a simple process (it was with the old carb) but this one is giving me fits. Any recommendations?
I have checked the timing on the E-Mag and P-Mag and they are good. Also checked for any obvious leaks or visual signs of issues. Compressions were all mid 70s.
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