Magneto Gear Help

Fearless · #1 09-07-2012, 05:37 PM

Today we were trying to time the magnetos on my 0320-D3G Lycoming. The left magneto is a 4373 impulse model. The problem is the gear on the right magneto. When I bought this engine core with the accessories the right mag had the impulse coupler adapter on that side. The magneto is a 4370 without the impulse coupler. If we put the magneto on with the adapter the gear is behind the internal gear and doesn't engage. If we put the magneto in without the adapter then the gear goes in front of the internal gear and doesn't engage. I believe this engine originally had two impulse mags on it. There is no marking on the magneto gear so I don't know the part number. I need to find a gear that fits this magneto that falls between the two distances. Does anybody know what gears fit this Slick magneto?

DaAV8R · #2 09-08-2012, 12:31 AM

The impulse and non impulse gears are different. The impulse mag also uses a spacer between the mag and the accessory case.

I think I have the gear you need. It sounds like you have an impulse gear but need a non impulse gear.

I'll send you a PM with a phone number. Call me if you are interested as I will be on the run tomorrow.

Robert

Fearless · #3 09-08-2012, 05:25 AM

Here's some additional information about my gear. It is 1 1/8 long. The rear of the gear is 1/2 long to a stepped up area. The stepped up area is about 3/16. The gear portion is about 3/8 wide.

Fearless · #4 09-10-2012, 05:58 AM

I still haven't found out what the deal is with this 4370 magneto. The gear thats on it is a non-impulse one. The mystery is why did it have the impulse adapter on the core I received and why won't it engage the gear inside the accessory case. It has the longer bolts on the right side for a impulse model. Another forum member suggested that I measure the distance on the left side from the edge of the accessory case to the gear inside to see if the left and right sides are the same. It is my understanding that a Slick 4370 magneto is a non-impulse model so the magneto with a non-impulse gear should just bolt right on. This is just not making any sense.

For those out there thinking of getting a core to rebuild - check everything you can think of. Also be very careful who you purchase the core from. Who would have thought an accessory would cause so much problem. The sad part is I have already had the magneto serviced.

659JR · #5 09-10-2012, 07:50 AM

The gear part number you need is a 61163 and it is completely different from the impulse style gear. You can change the studs in the accessory housing and the mag fastens directly without the spacer. The spacer is only used when you have the impulse coupling mag.
I can forward a pic of both gears if you like. I think I have a couple of new Lycoming gears for 150 if your interested. I may also have the gaskets and studs I can throw in.

Jesse