N941WR
Legacy Member
For those of you who are flying with E/P-mags and are relying on the RMSD (Run Mode Start Delay) to reduce backfiring, here is an important piece of information for you.
The RMSD is only active immediately after you add power to the ignition. If your engine doesn't catch right away, the RMSD is no longer armed and the ignitions will fire on the first revolution.
To re-arm the RMSD, you must cycle power to your E/P-mags.
This is especially important if you are testing the self power feature by cutting power to the units and pulling the throttle back until the engine dies. (around 800 RPM +/-)
If you hit the starter without cycling the power to the ignitions the cylinders will be full of fuel and the E/P-mags will fire the plugs. Remember, they fire on two cylinders at a time; on the compression and exhaust stroke.
Thus the fuel in the open cylinder (exhaust cycle) will light off and make for a very loud backfire out of the exhaust. This causes the pilot to RTB so they can CTS.
The RMSD is only active immediately after you add power to the ignition. If your engine doesn't catch right away, the RMSD is no longer armed and the ignitions will fire on the first revolution.
To re-arm the RMSD, you must cycle power to your E/P-mags.
This is especially important if you are testing the self power feature by cutting power to the units and pulling the throttle back until the engine dies. (around 800 RPM +/-)
If you hit the starter without cycling the power to the ignitions the cylinders will be full of fuel and the E/P-mags will fire the plugs. Remember, they fire on two cylinders at a time; on the compression and exhaust stroke.
Thus the fuel in the open cylinder (exhaust cycle) will light off and make for a very loud backfire out of the exhaust. This causes the pilot to RTB so they can CTS.
