Farmall C kicks back when starting

[Ken Monroe]

I put an external coil on my C with a mag on it. When I start it it will turn over a little then kicks back. If I hit the starter with the switch off, it will spin over fine. I can start it with spinning it over then pull the switch and it fires right off. It runs fine from then on. Is there some advance or something that the impulse still effects?

 

[rustred]

That means your impulse coupling is not working , causing the spark to be advanced causing the kickback. Is this a 6 volt or 12 volt ? If using 12 volts with a mag the engine spins over too fast and that could be your problems. Plus make sure your timing is statically set to TDC.

 

[Ken Monroe]

It is 6 volt. By static you mean ridgid or no impulse?

 

[rustred]

to have it fire right at TDC when the impulse trips. Then running and reved up it will
Advance. Check where it’s firing now. Might need to retard it a bit.

 

[jimtrs]

I put an external coil on my C with a mag on it. When I start it it will turn over a little then kicks back. If I hit the starter with the switch off, it will spin over fine. I can start it with spinning it over then pull the switch and it fires right off. It runs fine from then on. Is there some advance or something that the impulse still effects?

Timing is off. Kicking back is spark firing before piston reaches TDC, so it just pushes the piston back down, instead of letting it roll over to push piston down in the correct rotation.

This can severely hurt you when trying to hand start an engine.

Magneto fired engines must always have static timing set to fire at (not before) or very slightly after TDC

 

[teddy52food]

You may have to send that mag to me so I can try & fix the impulse.

 

[used red MN]

I put an external coil on my C with a mag on it. When I start it it will turn over a little then kicks back. If I hit the starter with the switch off, it will spin over fine. I can start it with spinning it over then pull the switch and it fires right off. It runs fine from then on. Is there some advance or something that the impulse still effects?

When you say you put an “external” coil on it do you mean you are using a battery powered coil and using the breaker points in the magneto to fire it. Static timing means with the engine stopped. The mag should still impulse, whether it is actually producing the spark or not. For static timing the engine is brought to TDC then the mag is loosened and turn to additionally wind the impulse spring, at the point the mag trips is where it is tighten down. Then come around again and watch the marks, the impulse should snap again as the TDC mark passes the pointer.

 

[Ken Monroe]

When you say you put an “external” coil on it do you mean you are using a battery powered coil and using the breaker points in the magneto to fire it. Static timing means with the engine stopped. The mag should still impulse, whether it is actually producing the spark or not. For static timing the engine is brought to TDC then the mag is loosened and turn to additionally wind the impulse spring, at the point the mag trips is where it is tighten down. Then come around again and watch the marks, the impulse should snap again as the TDC mark passes the pointer.

Yes, I am using it as a distributor.

 

[560Dennis]

do you have domed pistons?

 

[Ken Monroe]

Yes, I am using it as a distributor.

It was the impulse not working properly. Thanks for the help.

 

[DaveBN]

Glad you got it fixed. Thanks for letting us know.
Dave

 

[Janicholson]

It was the impulse not working properly. Thanks for the help.

Without the impulse working the timing must be set so it does not kick back (maybe 5 degrees or so) That is not sufficient advance because the mag has no advance other than the impulse at TDC and run timing well beyond 20 degrees. I think it will be way down on power (maybe 15 % or more) and have a tendency to overheat. Putting a real distributor on it is way better. Jim