1977 IH Cub Engine running rough

[Glen]

Hi,
If you are removing the whole Battery Ignition Unit to replace the points, be careful when you take it off the engine, or the drive gear that fits into the governor gear will slide out of the Battery Ignition unit, and you will lose the timing that it had. I'm not sure if anyone said that on here.
Also, stand the unit on end with the distributor cap end up, hold in the drive gear with your hand until you set it down on something. Then remove the rotor, and oil in the end of the shaft, use blocks maybe, to hold it upright, and let it sit on end, so the oil will run down the shaft and lube it. Then put the rotor on and turn it back and forth, while you hold the drive end from turning. This will help lube the shaft for the advance unit. Just an idea.
Here is a page from a Cub owner's manual showing the points and condenser. Notice it says "Lube Here" in the center of the shaft. Don't use the magneto info on the left side of the page.

http://www.cleancomputes.com/Cub/Cub%20 ... age-30.jpg

[Eugene]

If you haven't conducted the compression tests, do so before you proceed further.

If you have good compression on all cylinders, then you can proceed to ignition and then carburation. Why compression? Ignition and carburation can be perfect and the engine still lack power or run like crap. Ignition and carburation are easy fixes comparable to compression.

[pdwatts]

I have not had any luck with finding someone around me. Any chance I can get a quick lesson on retiming?

[gitractorman]

I know everyone pointed you in the direction of the ignition, and now you have ignition problems, so please proceed with getting that back in order. However, one of the biggest reasons I've seen which causes the condition you originally described (engine running erratic at high speed) is the linkage from the governor to the carburetor rubbing against the block, and not moving freely. The engine will run fine at idle, but at higher RPMs, where the governor is controlling the engine speed, the linkage rubbing against the block slows down the reaction time of the governor, making the engine rev up and hunt, not settling into a steady speed. Often if you back off of the throttle, the engine will settle down, because the governor is not needing to react as fast.

Anyway, since you just had the carb off, there's a chance that the rod is bent or bound up, and you just didn't notice it. It's quick and easy to check, see if the linkage has been bent or has dirt behind it making it rub against the block.

Good luck,
Bill

[pdwatts]

Thanks Bill. I did check the linkage and it seems clear, but it does move erratically when at higher RPM's. What you outlined is what I am experiencing. I bought a new Governer spring but not sure how to even get it on easily to see if that helped. I also cleaned and lubricate it all and not difference.

[pdwatts]

Glen, I will try that as well while I have the distributor out. Before I pull it, I think I have a brief outline of what to do.

1. Align engine to TDC and confirm indication on flywheel is lined but with indicator.
2. Mark rotor location
3. Mark Distributor body to block
4. Unbolt and remove.
5. Change points and condenser
6. Oil as required.
7. Reassemble making sure ALL marks are lined up properly
8. Turn the engine over and hope for the best!

[Papa's Cub]

PD, I'm surprised no one has mentioned adjusting the governor to carb linkage. My 66 was acting similar to what you are describing and I was advised to go to the how-to section and make the necessary adjustments. It solved my problem. Good Luck, Tom.

[pdwatts]

Well I finally got around to replacing the cap, wires, plugs, rotor, points and condenser. I actually pulled the distributor and it was very easy.

Put it all together and started right up, ran good. I think I still need to adjust the governer to carb linkage, but its running pretty good now. Even mowed a little with it.