Chainsaw Repair

Forgot a few points .I use a little LED light about the size of a ball point pen ,brilliant little thing .Always take the measurements in one direction ,the direction of rotation .If you go passed the very point of the port opening ,back it up and approach it again .

I use degrees of rotation starting at zero or TDC .Some like to use before TDC ,after 180 or bottom dead center and it gets damned confusing if you mumble jumble stuff than way .

Some use something like a 4 cycle wheel made by for instance Crane cams .Nothing wrong with them except this too gets confusing to guys like me that use a   360 degree wheel .As long as you know what you have though I guess it really doesn't matter .