Chainsaw Repair

   I have a couple of the 5° flywheels, but they both have broken fins and starter pawl issues. I have been running a couple of the std flywheels keyless, and just advance them a few degrees. The MC40 that I ran in West Plains was done this way. I set the advance using a degree wheel, I think it would equal a little less than a third of a key width for 5° advance.
    I have never heard of offset keys for these engines.

One of my 125's that came from California has an off set key .

Keep in mind though unless you are running an "atom Arc"( solid state ) type trigger all you are doing is shifting the flywheel ahead .This is to keep the fire point in the max lines of magnetic flux for the hottest spark . With points they still need to be "mavericked" .In other words reset from 18 thou opened to maybe 22 or so .You'll  have to play with it because quite frankly I forgot exactly how much it is .

The solid state triggers switch at the max voltage generated from the coil .When the sine wave shifts negative ,they fire .

    All the points are there for, is getting the engine started, and up to speed. While running at speed they never completely close, and the firing point is adjusted by flywheel position. I have proven this by installing a toggle switch between the points and coil, and mounting it on the saw handle. The point at which the spark begins to maverick without the switch however, is adjusted by breaker point return spring pressure. I have seen some special points, made some aftermarket kart mfg. that had a Z spring, making it much easier to bend and adjust the pressure.
   The good part about running an engine with maverick spark, is that the points can be set conservatively, and yet still get maximum advance at full power. Saves them starters!