[Michael Burbidge]

I just received my new B&C Starter. There's lots of warning and talk in the installation docs about kickback, and making sure the non-impulse couple mag is disabled during startup.

Last year I installed one p-mag. It replaced my impulse coupled slick mag. So I have p-mag on the left and slick on the right.

I have the typical four position ignition switch. When I installed the p-mag the instructions said to remove the jumper that disables the non-impulse coupled mag.

The B&C installation docs don't mention EI, so I'm wondering if I should re-install the jumper so that my slick mag is disabled during startup. My p-mag has version 40 software so it delays the spark past TDC during startup.

Does anyone else have a similar setup? If so what did you do? Have you had any problems with kickback?

Thanks,
Michael-

 

[tim2542]

A 4 position switch like you have will have provision to ground the non-impulse magneto. Since you still have a non-impulse mag installed, make sure the P-lead to it is grounded when the switch is in the start position.
You should be able to test this with the master switch OFF so the starter won't engage, have someone hold the switch in start, while you check that the P-lead is in fact grounding while in the start position. Use appropriate caution of course.
Tim Andres

 

[Canadian_JOY]

The B&C installation docs don't mention EI, so I'm wondering if I should re-install the jumper so that my slick mag is disabled during startup. My p-mag has version 40 software so it delays the spark past TDC during startup./QUOTE]

Yes, the jumper is definitely required to "kill" your non-impulse mag during cranking.

The issue is with the non-impulse-coupled mag because it is set to fire at (depending on your engine and mag) something like 25 degrees BEFORE top dead center. If this mag is operational during cranking, it may cause a cylinder to fire before the piston is at the top of its travel. This is kickback. While the B&C starters are very stout, kickback can be strong enough to break any starter.

 

[RFazio]

Their is another problem using the key switch.

The 4 position switch you are speaking of has another problem. I had a couple kick backs using it with the right mag properly grounded on crank. What happens is that you crank, the left mag is firing and the right is off. You are pulling in fuel and air to ignite. The engine is almost ready to go but not quite. You crank a few revs and she doesn't catch so you let go of the key to stop cranking. The second you let go of the key the right mag fires with the engine turning very slow and you get a fire in one cylinder that did not fire with the left mag. Boom kick back! After a few kick backs and ruining a starter, I added a separate right mag grounding switch that grounds the right mag on start. After its running the right mag is then ungrounded to run.

 

[Bob Martin]

Thanks

The 4 position switch you are speaking of has another problem. I had a couple kick backs using it with the right mag properly grounded on crank. What happens is that you crank, the left mag is firing and the right is off. You are pulling in fuel and air to ignite. The engine is almost ready to go but not quite. You crank a few revs and she doesn't catch so you let go of the key to stop cranking. The second you let go of the key the right mag fires with the engine turning very slow and you get a fire in one cylinder that did not fire with the left mag. Boom kick back! After a few kick backs and ruining a starter, I added a separate right mag grounding switch that grounds the right mag on start. After its running the right mag is then ungrounded to run.

Very Good info.......Thanks for pointing this out! With a solution too.