# 420 ignition problem



## Bruster (Jun 23, 2018)

Have a 420 with the b48G onan. Wife was mowing the other day and it just died and wouldn't restart. So after poking around with my meter I have 12.6 to the positive terminal on the coil (He166-0772)But when I ohm it I have a reading of 41ohms...which seems super high. Does anyone know what the resistance reading should be in these coils? ID hate to drop 200bucks on one and it not be the issue


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## sixbales (May 18, 2011)

Howdy Bruster, welcome aboard the tractor forum. 

I found the following posted by WSJ on the YT forum:

Testing Electrical Systems with a Digital Multimeter

http://assets.fluke.com/appnotes/automotive/beatbook.pdf


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## sixbales (May 18, 2011)

Bruster,

On an old Ford tractor with a 12VDC system, the coil primary resistance is about 3 ohms ~ 4 amps current flow. That's between the + and - terminals.


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## Bruster (Jun 23, 2018)

guess I should have specified where I check..i went between the towers to get the 41ohms.

Checking from each tower to both positive and negative im open.


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## sixbales (May 18, 2011)

Bruster, you can get that coil on ebay for $45. See ebay item #292537099865


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## Bruster (Jun 23, 2018)

Yeah I saw that..mine doesnt have that condenser(silver bullet looking deal)


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## RC Wells (Dec 26, 2008)

Take a look at this You Tube to locate the points and condenser: 




There was a solid state conversion for tha engine, but I am unsure if they are still available.

Here is a troubleshooting procedure for most Onan Twins:


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## sixbales (May 18, 2011)

Bruster,

Excellent information from RC Wells. You don't have a condenser?? Maybe it already has a conversion. Incidentally, you can get Onan points for that engine on ebay for $50. EBay item number:
221994038749


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## Bruster (Jun 23, 2018)

I take that back..after removing the cover I found the points and condenser.

I'm going to order that kit from ebay and give it a try.


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