Thackery - Magneto Problem

[Eugene]

I was just given a 50? cub by my neighbor, which he bought at auction some time ago and could never get running. I have been following this string about Brianj's cub. I have tried most but not all of the suggestions posted. I have new plugs, new wires, checked the kill switch, checked spark and checked timing, replaced condesor and points. After many many tries with only the occasional back-fire, I noticed on rechecking the timing at TDC that the rotor was about 180 out. I readjusted tried all kinds of things again. Checked the timing at TDC. Looked like the rotor was a couple of teeth off. Readjusted. Cranked a bunch, rechecked at TDC and was about 180 out again. I took the J4 mag off cleaned off junk and did the points and condesor at that time. I checked to make sure that the rotor was not skipping teeth from the distributor gear, I don't think it is. Well I rechecked the timing and adjusted at TDC and it was out again. I have a J4 magneto on but the coil has been bypassed and run through a new 6v coil. so the old mag is just a distributor now.
Any ideas, I would love to hear something. Thanks a bunch.

Thackery

[jim turner]

well here is what I would do take #1 plug out and hold my thumb in the hole and have someone crank it for you when you feel the compression turn the crank pulley to line up with the pointer, then look and see where the rotor is pointing now that only tells you the rotor it in time or not, then you have to see if the points are in time as well.

[John *.?-!.* cub owner]

eugene, check if the drive pinion (gear that turns rotor) is wallowed out and slipping on it's shaft. I've seen that happen a time or two.

[Jack O Donovan]

You mention that the mag had bean changed or converted with a coil, Now you need a batt,or it won't start or fire

[Bigdog]

If it won't hold time, something must be stripped in the distributor drive.

[rick 48 cub]

Since you are still in the business of experimenting try this:

While someone else is cranking the engine - see if you can get a spark with a wire off of a spark plug. Hold it real close to the engine block so that you will even notice a weak spark.

If you do get a spark the problem is more likely timing.

On the other hand, it sounds like someone really futzed with the original iginition. I bet that is where your problem lies. Perhaps you can start over with a new magneto/distributor assembly from JP Tractor Salvage.

Rick

[Eugene]

Actually it's Thackery's post from a previous thread.

My thought is that one of the pins holding a gear to it's shaft in the magneto is sheared. As John and Bigdog suggest, something in the magneto is stripped or sheared.

Since the coil in the mag is nonfunctional. Suggest a complete disassembly and rebuild - or purchase a rebuilt magneto.

Eugene