Farmall H Magneto Question (American Bosch MJB4A-308)

[prairieplow07]

Will an American Bosch MJB4A-308 work on a Farmall H?

I have the same American Bosch magneto on my Farmall M and it runs great.

Thanks.

 

[Janicholson]

The mounts are interchangeable. Total advance between the impulse trigger point, and running advance should be checked against the M max advance (and modifications to that M's compression and rpm settings)to assure full power. Jim

 

[560Dennis]

Do they have a 35 degree advance ?

 

[prairieplow07]

I am not sure. If that is what is needed, I can take the mag to a shop and find out. I like having mags so I don't have to keep a collection of batteries. These are just show / play around tractors. A friend was cleaning a shed and found the mag and gave it to me.

Thanks.

 

[rustred]

i do not know of any difference in advance on the ihc h4 mags and they use them on all the different models. so dont see why that mag would
be any different.

 

[Jim Becker]

The version of the H-4 mag used on the letter series tractors has a 35 degree lag angle. Many magnetos from companies like Wico and Bosch have adjustable lag angles controlled by rotating the stop for the impulse pawl. Others may use different couplings to change the angle. A quick web search found comments that went both ways on the Bosch MJB. So maybe it depends on what spec they were building/selling to. You better check it over to see that it is at least close before installing it.

 

[prairieplow07]

Thank you.

 

[560Dennis]

H4 magneto ,35 degree lag is to keep you from getting kick back on starter ( hand cranking) . You dont want that ,trust me . Dont want you posting anything about injury to your arm ,or friend or family members getting hurt.