Howdy Everyone. Sorry in advance for the long reply. The short of it is, in my opinion, kickback is a simple timing problem. Pmag has suggestions for the issue. The Pmags have a jumper wire at the Pmag connector that can be installed or not to adjust the advance curve. Having the jumper installed renders a less aggressive curve, no jumper installed is more aggressive. Users should also know what firmware version their mags have installed.
Board version and FW version are imbedded in the “VL” code on the ignition data label.
“VL XXYYZZ:
XX is the board number
YY is the FW version
ZZ is internal tracking"
I suggest reading these documents:
Go to the Pmag website, at the top, hover over:
MANUALS/GUIDES/TOOLS
Click: DOWNLOADS
Click: 114 MANUAL
See page 13, Variable Timing.
Also check out the TROUBLESHOOTING GUIDE.
Copied from their TIPS and TRICKS page:
"Low Mass Props: Kick-Back Precaution
(NOTE: This issue has been addressed in firmware V40, and after, by adding a 4 degree startup firing lag.)
Lightweight low mass props, by their nature, have less flywheel effect on the engine. This allows the engine to decelerate much quicker as the starter motor pulls against each compression stroke, and as the engine approaches TDC – where the plugs fire for startup. Under the right conditions, the combination of low mass prop, weak or undersized battery, corroded terminals, cold engine, long cable runs, tired starter (or any combination) can cause the engine to come to a (virtual) stop by the time it reaches TDC. At this point there is a 50/50 chance the engine will move forward or backward (a so-called kick-back) when the plugs fire. While the ignition may be performing as designed, the results are the same. Fortunately, there is an easy defense.
Simply re-time the ignition with the engine parked two or three degrees “AFTER” TDC (instead of “AT” TDC as you normally would). AFTER TDC means (from the TDC position) rotate the prop in the normal direction of travel to your revised target timing mark. Note: This will also slightly retard the operating advance range, but this small amount is not likely to be noticeable for most flyers. If desired, the shift can be nulled with the EICAD interface."
Your Aerosport Power engine plate will have the timing recommendation stamped on it.