Magneto Timing

bwillett · May 25, 2020

My 1936 WC Allis has an American Bosch magneto model MJC40-302 on it. I took the cap off of it to check it out because I have been having problems starting it after a rain. It sits outside but I have a bucket over the intake and a can on the exhaust. Any way, I reset the points to .020" and then tried to put the cap back on.I can't get the mark on the drive gear to line up with the line on the rotor.

Also, I am unable to find the timing marks on the flywheel....

TIA.
Bill

shaun wallace · May 25, 2020

Remove cover on bottom. They time down there. there is "F" mark and TDC mark.

4wdtom · May 25, 2020

and you line them up with the center line of the bellhousing casting.

bwillett · May 25, 2020

I removed the top cover and both of the bottom covers, and turned the flywheel over 4 inches at a time and still could not find any marks.

Rich'sToys · May 27, 2020

Is the mag off the tractor?

You should be able to get it close by bringing no. 1 cylinder to TDC on the compression stroke. Then turn the mag till it fires on the no. 1 position, then put it in the tractor.

Or am I misunderstanding the question? If so, I apologize.

bwillett · May 28, 2020

Mag is still on the tractor. I can' get the mark on the gear and the mark on the rotor to line up. Every time I get it close, it jumps past it.

bwillett · May 28, 2020

"cant" get it to line up.

Bevan · May 28, 2020

another thing I dealt with on my 38. You are going to have to build tension in that mag. The coupler, if properly set on the motor, will require you to turn the mag to the passenger side, lock in with the drive and then rotate it verticle. If done right with the F in the verticle position and on the compression stroke on #1 your rotor arm should be pointing at the top passenger side post. That is the #1 cylinder post. The gap should be .20 when the points are riding the top of the lobe.

Magneto Timing

bwillett

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shaun wallace

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4wdtom

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bwillett

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Rich'sToys

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bwillett

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bwillett

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Bevan

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