Model L/Hercules engine with wico x magneto

DGinVT

Member
On my JD Model L/Hercules Engine, model NXB engine,and Wico X Magneto the impulse is supposed to trip when the "DC" mark is at the bottom of the timing hole. Mine trips well after that. I have had to loosen the impulse hold down screws and move the impulse ring clockwise as viewed from the front(gear end) about 2 divisions clockwise to get it to trip at the bottom of the hole. When I got the magnetos from John Brillman( to replace the Wico C ) , the impulse was set at 1 1/2 divisions(about 20* lag)which agrees with the reference chart for Wico X magnetos . It had no trouble starting and running at the 1 1/2 (20* lag) but the impulse was about 1/4 to 1/3 below the timing hole, making the piston well below the timing hole. I am missing something here?,It's been about 40 years since I have done magneto work. What is the correct setting for the impulse ring?
 
Lag setting is set to match the lag angle of the impulse cup.

It is NOT used to fine-tune when the installed mag impulse trips on the engine.

I would GUESS the timing is a tooth off.
 
On my John Deere with a Hercules engine, the magneto is slotted and all I have to do is loosen it a little bit and rotate the magneto until the timing works line up. If that is the question that you are asking.
 

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