Won't seam to fire

Tessiers Farm · Post by **Tessiers Farm** » Mon Sep 03, 2012 5:08 pm

1950 MC, can't get it to fire, new points and condenser, weak spark to plugs. There was no battery in it when I got it so I put my 6v battery in it. What happens if it has been converted to 12v. No writing on the coil, what else should I be looking for? I really don't have much time in it yet, but I usually have pretty good luck with these things.

Post by **JD40c** » Mon Sep 03, 2012 5:32 pm

Can you ask the previous owner if it is 6 or 12V?

Tessiers Farm · Post by **Tessiers Farm** » Mon Sep 03, 2012 5:38 pm

Previous owner has passed away, his son didn't even know there was a difference. I just picked it up this weekend, for basically scrap price. I will bring it into the shop in a couple of weeks and see what I got. Fluids look good, turns over easy, has very weak spark, float is stuck in carb, was just hopeing for a quick fire enough to back it off the trailer, no such luck but she has potential.

jtrichard · Post by **jtrichard** » Mon Sep 03, 2012 5:51 pm

alt. or gen? if alt its 12v if gen look at gen for stamp or tag it should say 6 or 12 or check regulator it should say you can also disconnect the gen and reg and start it on 12 even if it is 6 just to get it home

krusty · Post by **krusty** » Mon Sep 03, 2012 6:17 pm

crank that baby with a 12V battery in it and if there is any will in it, it should at least fire a few times. I had put a new 6V battery in mine even though it was still 6V and it was just too weak to get it going consistently. Now if it fires you should change it over to a 12V coil or you will burn it out soon enough

drummer · Post by **drummer** » Mon Sep 03, 2012 7:15 pm

To test for 12 volt coil check the resistance across the negative - positive terminals. A 12 volt will read 3.1 to 3.5 ohms and a 6 volt in the 1.4 to 1.6 ohm range. I've found over the years that most times you either have a bad set of points or a bad set of plugs when it comes to no or weak spark. Also on the coil with 12 volt the negative terminal goes to distributor and positive to the switch. Its the opposite on a 6 volt positive ground. Keep in touch Drummer

jtrichard · Post by **jtrichard** » Mon Sep 03, 2012 8:10 pm

if some one put a 12 generator on it (which i doubt) it could still be positive ground and there two types of 12v coils one that has the resistor built in and one that requires an external resistor the best one to use is the one that requires the external one as you can put HOT START on it

Tessiers Farm · Post by **Tessiers Farm** » Sat Nov 03, 2012 4:06 pm

put a 12 volt battery in and she fired right up, perfect spark and runs good.

jtrichard · Post by **jtrichard** » Sat Nov 03, 2012 5:13 pm

that's good but if it is a 6volt coil or a 12 volt that needs a external resistor you will fry the points in short order

Scottyb · Post by **Scottyb** » Sun Nov 04, 2012 2:34 am

all right, it is running!!! man that feels good when it fires up and you can rev it up and it doesn't knock or sputter and it sounds good. Yea you might burn a coil or some points because it is not the exact right setup but but it runs!!!! You know at that moment that you have a engine that is going to do what you hoped. It runs and it runs nice. hopefully, tomorrow it can be tuned up. you have and will have awesome advice on how to do make it run properly, Congrats on getting it going.
Scott

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