H4 Magneto

Sat Sep 01, 2012 7:01 pm

I will be putting the magneto back on my McCormick Deering W4 tomorrow, thank you Al (Super A) for your help. The one question I have is that after I set the engine to TDC on cylinder #1, where should I turn the magneto to, I have heard that I should line it up so that the rotor points to the coil wire on top, but I have also heard that I should point the rotor toward the number "1" that is marked on the plastic cap. Any help in this matter would be awesome. I seem to be able to time the mag on my Cub in a matter of minutes but for some reason this one is throwing me off.

Thanks,
A.J.

Re: H4 Magneto

Sat Sep 01, 2012 10:34 pm

A.J., the timing procedures are exactly the same as those for the Cub.

Align the timing mark on the pulley, so that #1 is TDC on compression stroke. Rotate the mag so that the rotor is pointing to the #1 tower. Install the Mag and then rotate the housing towards the block. With the ignition off, rotate the engine one full revolution till the timing mark aligns once again (#4 now at TDC). Then with the ignition still off, rotate the mag away from the block till the impulse snaps. You will now be timed.

Re: H4 Magneto

Sun Sep 02, 2012 12:49 pm

I think I can handle that. I must ask one stupid question though, which post exactly is the number 1 post. The number is in the middle of the two posts, I am assuming the number 1 post is the one to the left. Sorry for the dumb question.

Re: H4 Magneto

Sun Sep 02, 2012 10:57 pm

DelValCub wrote:... which post exactly is the number 1 post. The number is in the middle of the two posts, I am assuming the number 1 post is the one to the left. ...

The number one tower is (should be) the one at the top of the cap closest to the coil.

Re: H4 Magneto

Tue Sep 25, 2012 11:08 am

I have a H4 magneto and have had it apart. The rotor gear timing looks as if I have choices as to advance, retard or set at the center of the match marks. Is there a spec for setting this gear timing for a 1952 Farmall H?
redbird

Re: H4 Magneto

Tue Sep 25, 2012 11:28 am

GSS-5035 Service Manual Magnetos. Click the link, the manual details the H-4 Magneto beginning on Page 41.

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