Corrosion on Distributor cap and rotor

[J3 Driver]

So my son’s cub has developed a slight miss at idle and then when getting bogged down really tonto miss and die out. I thought it might be fuel flow but checked all that and it was set up like it should be.

Next up was the ignition. Pulled the distributor cap and looked at it and the rotor and noticed a lot of corrosion. So I’m order a new cap, rotor, points and condenser to get it back on track. My question is what would cause this. My son runs his cub just about daily for at least 15 minutes so it wouldn’t be from lack of use. Is there any sort of protectant I can’t put in he contacts.

Thanks.

Keith.

[Don McCombs]

Moisture/condensation. WD-40.

[Frozenstate]

Put silicone dielectric compound on the cap contacts and on the rotor. Keep it away from the points. That helps.

[tst]

use a cap with brass inserts, not aluminum

[J3 Driver]

Got it all fixed up last night. Think I found the problem. The fact the the gap was at least an 1/8 inch certainly wasn’t helping things. I’m surprised the thing actually ran at all.

[Glen]

Hi,
TM Tractor has points and other tune up parts. It says the points and condenser are Case IH parts.
Below are pages from the late 1955 Cub owner's manual showing servicing the points.

http://farmallcub.com/rudi_cub/www.clea ... e%2041.jpg

http://farmallcub.com/rudi_cub/www.clea ... e%2042.jpg

You can scrape and sand the corrosion off the cap contacts, and rotor, and see if they look good. If they are burned much, new parts are better.

The rotor should turn a few degrees when it is on it's shaft, that is the spark advance mechanism movement.

Put a few drops of motor oil on the felt in the end of the shaft the rotor is on, like it shows in the manual pic. The shaft can get tight without lubrication, then the spark advance won't work.

You should set the ignition timing with a timing light after replacing the points, the timing affects the starting, and engine power

[ScottyD'sdad]

Be careful with aftermarket points. Some have brittle spring, that break. Some stay open, due to weak springs. I recently had a cub that wouldn't start, after sitting all winter. Points were stuck open. Aftermarket points put in by PO.

Ed

[CharlieK]

DON'T USE AFTER MARKET POINTS

[Glen]

Hi,
At least one of the experts on here has posted the number of the NAPA points for the Cub before.

[J3 Driver]

All the replacement parts I used were genuine IH parts. In the long run they aren’t really more expensive. And I did use a light to time everything one it was back together. Th cub runs much better now.
Thanks all.