Farm Equipment - Allis C 12v conversion

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Allis C 12v conversion

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=207321
Printed Date: 05 Jul 2025 at 11:20am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Allis C 12v conversion

Posted By: Shane1304
Subject: Allis C 12v conversion
Date Posted: 02 Jul 2025 at 7:47am

forgive me I'm sure this type of question has been presented before.In order to change over my 6v system to a 12v system, do I need to change anything with the magneto? I understand the change in grounding and the alternator conversion over the generator and wiring, just not sure how it affects the magneto.

Replies:

Posted By: PaulB
Date Posted: 02 Jul 2025 at 1:47pm

Changing to 12 volts on a C will have no effect on the magneto, except when spinning a 6 volt starter with 12 volt could turn the engine over fast enough to override the impulse and not allow the engine to start with the advanced timing. Also on the smaller tractors switching to 12 volts it will hasten starter ring gear wear and could also lead to bendix problems. although many say they done this without any troubles. Do you feel lucky?

Having your starter rebuilt as a true 12 volt unit will slow the starter speed down enough to eleminate the above mentioned issues.

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If it was fun to pull in LOW gear, I could have a John Deere.
Real pullers don't have speed limits.
If you can't make it GO... make it SHINY

Posted By: steve(ill)
Date Posted: 02 Jul 2025 at 3:08pm

magneto has a kill switch to ground it... no power to the mag..

I have several tractors that all run 12v systems / alternators.. with the original starters.. If it is setup right, with a good mag and good carb... the motor should turn over 1-2 times and start.. Will not have time to get up to "fast rpm" ....Think of an engine that is crank started by hand.. Only turns over ONCE and its running...

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Like them all, but love the "B"s.