Nice build, Doug. The finished engine looks stunning. I'm curious about the weed eater coil. Does it have points or electronic circuitry built in? Or is it just a coil activated by the magnets on the flywheel? If the latter, I'm surprised the will generate enough voltage for a spark.
Chuck
Thanks for the kind words...
What you see is all that is there, just the coil and lead wire. I used two neodymium magnets on the flywheel, maybe overkill, but I had them from a previous project. The coil produces a BRIGHT blue spark all the way down to about 500 RPM, then it fades away. This is not an issue, because the smaller and lighter flywheel I used can't really get the engine around to another compression stroke at that RPM anyway (tons of compression with the Viton o-ring). It is the same coil arraignment used on my Webster and it works beautifully.
It is strong enough that I have been zapped a few times pretty hard by accidentally touching the kill pin on the coil while holding the engine. Not quite a tazer, but I did let go of it very quickly!
Doug