1954 farmall cub - point gap with worn cam lobes

[p3210]

Hi Folks,
Long time stalker here - hoping to get some guidance (I know just enough to get myself in trouble).

1954 farmall cub (Ruby), 6 volt positive(?) ground with points/distributor.
Ruby in the middle of mowing suddenly shut down and wouldnt start so I changed the ignition coil, condenser, rotor, and points, and then checked timing; timing set at TDC would only advance half-way to the second mark. When I took ruby back out to mow the tractor would mow for 30-45 minutes and then die; then restart a few minutes later. After reading discussions on this website and messing with Ruby... and getting the same result... I decided to recheck the points.

I reset the points and decided I should check the gap at all four cam lobe corners because I know there is wear. I found that the "wear difference" is larger than I expected.
Here are the point gap numbers I am getting (starting at plug 1 and going counter clockwise around the cam lobe/rubbing block):
006 (plug 1 position)
043
055
025
(FYI for gaps greater than 035 I combined "feeler blades" so values arent the most accurate)

006 to 055 seems like a huge difference. Is the wear really bad and I have no choice but to replace the distributor? Or should I keep as is and hope for the best? Or should I increase the gap to move plug 1 (at 006 gap) to a larger gap; this would increase all the other gaps... and maybe increasing the gap is OK?

Any thoughts/input on the above is greatly appreciated.

Thanks much
Phil

[Jackman]

Not sure how bad those measurements are fir a nice running Cub however if it’s worn out maybe consider an upgrade to electronic ignition. I like my electronic unit however it’s still new to me but my Cub has never started and ran so nice

[Jim Becker]

My first thought is that the problem may be in the distributor shaft bushing rather than the cam. Check the shaft for side-to-side movement.
(At least I think there is an actual bushing in the housing, maybe not.)

[SamsFarm]

My first thought is that the problem may be in the distributor shaft bushing rather than the cam. Check the shaft for side-to-side movement.

This ⬆️ sounds like a reasonable explanation.

Not saying it is impossible, but dont think the distributer shaft lobes would wear so uneven. Surely I would think it was made hardened and ground

[Glen]

Hi,
I think there is a bushing in the distributor part of the Battery Ignition unit.

Someone on here replaced it before, I think.

Below is a page from the Cub parts manual showing the IH distributor, the bushing isn't shown in the pic, but is at the last item in the description.

http://www.farmallcub.info/manuals/cub_ ... 012-28.jpg

If the bushing is worn, it could be from nobody greasing it.

The Battery Ignition unit should be greased every 500 hours of use, the Cub operator's manual says.
It has 2 plugs for grease fittings.
You remove the plugs and put in grease fittings.
The holes are bigger than other grease fittings on the Cub. You need to buy a grease fitting the size of the holes, if you don't have any.
You can buy 1 fitting and move it to the 2 holes, greasing them 1 at a time.
They have said on here to put the plugs in again after greasing it, so it doesn't get greased too often.

Below is a page from the 1955 Cub operator's manual telling about greasing the Battery Ignition unit.

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

[staninlowerAL]

FWIW, I had a similar problem with a late 60's F150 many years ago. I discovered that the distributor shaft had side play and was worn to the point that when the points gap was set correctly, then after starting and running the engine for a short time it would stop running. Reset the points gap and repeat. I replaced the distributor and instantly solved the problem. Happened on a road trip on Christmas Eve, about 1969. It might have been a worn bushing, I replaced the complete unit with a reman one.

[Don McCombs]

Maybe, maybe not…

https://brillman.com/product/delco-dist ... -shim-kit/

[tst]

yes the bushings can go bad as no one greases them, just grab the rotor and try and see if the shaft wiggles side to side, if so bushing is bad, if its tight lobe is worn

[Boss Hog]

may be a combination of both, the cams do wear down . I have seen both bad or just one of the two. An electronic ign will take care of the problem
Boss

[p3210]

Thanks all for the quick response and the knowledge.
The two distributor points have never been greased.... I will buy grease zerks for those points and do that (I wonder why zerks werent originally included in the design?).
The distributor shaft does have a small amount of play... The cam lobes are worn...Not sure which is the main culprit but either way... 1) it sounds like everyone agrees the point gaps are too large, and 2) I need to grease the distributor shaft.
Bottom line - I seems the installation of an electronic ignition is in my future. I bought one years ago (pertronix 1442p6), installed it... but it didnt work. Either I installed it incorrectly or, from what I just read, maybe the 6volt battery was low. I will try again.
Thanks again to all for all the info and guidance!
Phil
.

[Gary Dotson]

While I’m a big fan of the Pertronix ignition conversion, I’m not too warm on using them on 6v tractors. The battery has to be in very good condition and well charged or starting problems will arise. They are very sensitive to voltage.
Your difference in point gap is for sure excessive. I’ve encountered them, before, where somehow, someone managed to bend the shaft. I would pull the distributor, put it on the bench and give it a thorough inspection. Used distributors are easy enough to find and they seldom have the excessive wear you’re seeing.

[Glen]

Hi,
JP Tractor Salvage at the bottom of the page might have a used Battery Ignition unit, if you want to replace it.

[Jim Becker]

If you get a replacement, be sure to get a unit from a Cub (symbol D at the base).

[Glen]

The D is stamped in the side of the round base, where the timing adjusting clamps are.
It might not be visible when the distributor is on the Cub, if it is on the engine side of the base.

The parts manual page I posted above shows where the D is, in the picture.

[p3210]

Thanks folks for the info on a replacement distributor.
Since I already have an electronic ignition I am going to try and make that work... If I cant get the electronic ignition to work, or if I find the electronic ignition to be a pain, then my plan B will be a replacement distributor.
Thanks again to all for the advice and guidance!
Phil