magneto

[Tom Roe]

I have  an HG42 that Ijust put  a new engine out of an OC3 in My HG manuel has timeing instruction for a WIXCO mag ,however this engine has a FAIRBANKS MORSEmag on it.We are haveing trouble timeing it .1we can't find TDC by  putting something into the cylinder and watching it rise as we rotate the engine.2 we put in an aux transmission which went great but we may have put the flywheel on wrong.As you can see we are not mechanics .how can correct the timing without taking thevengine out .thanks from a newbe who can hold a wrench

[hotratz]

Put your finger over the spark plug hole as you rotate the piston in number 1 upwards. If you feel compression you are coming up on TDC of the "compression" stroke. This is what you want. If you don't feel compression you are coming up on an exhaust stroke. If you don't feel compression on either stroke, something  bad has happened.

When you get close to TDC on the compression stroke look at the timing hole on the front of the clutch housing. You should see the letters "SPK" appear on the flywheel as you rotate. This is the position you want the mag to fire. I didn't think it would be possible to easily index the flywheel on the crank wrong but I've not had that portion apart myself.