Page 1 of 2

Cub Farmall will not start

Posted: Tue Sep 17, 2013 2:05 pm
by David D
I just had my cub worked on. They bought it back and it would not start to come off truck. It acted like a dead battery; it didn't want to turn over. Finally it started. They said it had been sitting for a while. I drove it around it ran great. I shut it off and an hour later came back and it work not start. They came the next day took the starter and had it checked. Starter checked OK. Put new fittings on tractor started right up. Few hours later the cub would not start again. I had the new battery check it was OK. I did notice that the voltage meter went into the negative when I hooked it back up. Cub does not want to start. It is laboring to try to turn over. HELP!!

Re: Cub Farmall will not start

Posted: Tue Sep 17, 2013 5:01 pm
by Rudi
David:

G'day to you and sorry to hear you are having problems with your Cub. I would recommend that the first thing you do is check all the grounds and connections to make sure that they are clean and bright metal including the fasteners. Start with the battery and work forward to the starter. Once those have been tested and confirmed good, try it again. Should start. Second thing to check is the battery itself. Grab a hydrometer and see what it says if your batter has caps that come off for inspection/filling. Check the level of the electrolyte. If it is down and the fins are dry .. fill with distilled water. Recharge the battery. If you have a load meter you can check it that way as well.

Cubs are not that difficult to work on. Many of us are not mechanics ... we just tinker. If you follow the manuals you can easily maintain and repair your own Cub. All the information you need to know is contained in the links below. I would strongly suggest that you grab yourself a cuppa :coffee: or favourite beverage .... and set a spell reading the Owner's Manual and studying the Blue Ribbon Service Manuals. It will be well worth your while.

Image to Farmallcub.com :big smile: Forum Family. And you have come to the right place for all things Cub related. If you click on the Site Rules, Regulations, & Important Information, it will point you to :arrow: the Welcome Wagon wherein you will find links to many useful sites and topics. One of the most important resources are Owner's Manuals, Parts Catalogs and Service Manuals. The Cub Manual Server is the home of the jpg versions and the [url=http://www.farmallcub.com/[ Sorry, direct links to manual section is not allowed. ]/index.php]PDF Manuals[/url] -- well the pdf's of course :wink: Enjoy!.

Re: Cub Farmall will not start

Posted: Tue Sep 17, 2013 6:22 pm
by Mike in Louisiana
Why was the cub sent to the repair shop and what were they supposed to do. Is it 6 volt or 12 volt neg or pos ground?

What year and is it magneto or distributor?

Re: Cub Farmall will not start

Posted: Tue Sep 17, 2013 6:49 pm
by Eugene
Battery good, starter good, laboring cranking over engine during start. The poor engine cranking over is something between the battery and the starter. Suggest answering questions posed by previous posters.

Couple of possible answers and things to check out. Corrosion in battery cables, corrosion in battery cable terminals and battery posts or poor grounds. If it's got a solenoid - possible.

Regulator not polarized - discharging battery.

Re: Cub Farmall will not start

Posted: Wed Sep 18, 2013 8:00 am
by David D
• Okay this is what is happening with my tractor.
• My tractor still will not start with battery. The starter was taken off and taken to A & L Truck Electric Inc. They tested it and said the starter checked out. They put a new nut and clamp for the battery and ammeter cables on it. When the starter was placed back on the tractor and tried, the tractor started up like it use to do.
• A few hours later I tried to star the tractor. The tractor still continues to labor cranking as though the battery is almost dead.
• I checked the battery connections they were good. I then took the battery tot Napa Auto Parts and had it checked. The battery (new) was good
• I reconnected the battery and checked the connections between the battery and starter. They are good.
• The tractor does start by hand cranking. It takes 3 to 5 good cranks and does runs good once started.
• I did notice when I was connecting the battery, the Ammeter meter went into the negative. The battery is hooked up properly with a positive ground. The Ammeter meter does go into the positive when the tractor is running after being started with a hand crank.

Re: Cub Farmall will not start

Posted: Wed Sep 18, 2013 8:12 am
by Mike in Louisiana
still sounds like bad connections somewhere. are the battery terminal ends the kind that have two bolts holding the wire to the clamp? if so strip the wire back and redo the clamp.

Re: Cub Farmall will not start

Posted: Wed Sep 18, 2013 8:20 am
by Jim Becker
David D wrote:I did notice when I was connecting the battery, the Ammeter meter went into the negative.

This is your problem. The ammeter shouldn't even wiggle when you connect the battery. You have a short or leak that is draining your battery. Try isolating (disconnecting) parts of the electrical system until it quits discharging. I good place to start is to take the wire off the "bat" terminal of the voltage regulator. The cut-out relay of the regulator may be stuck shut allowing discharge through the generator.

Re: Cub Farmall will not start

Posted: Wed Sep 18, 2013 8:22 am
by Smokeycub
It may be a good time to upgrade the cables, especially if they aren't heavy enough. Someone could have replaced them with something too small and if corroded can't carry enough amperage to the starter. Could be the starter switch itself.

Re: Cub Farmall will not start

Posted: Wed Sep 18, 2013 8:25 am
by David D
Eugene wrote:Battery good, starter good, laboring cranking over engine during start. The poor engine cranking over is something between the battery and the starter. Suggest answering questions posed by previous posters.

Couple of possible answers and things to check out. Corrosion in battery cables, corrosion in battery cable terminals and battery posts or poor grounds. If it's got a solenoid - possible.

Regulator not polarized - discharging battery.




How do I polarize the Regulator?

Re: Cub Farmall will not start

Posted: Wed Sep 18, 2013 8:58 am
by Eugene
You haven't answered the questions previously posted. Year of tractor and model? But since you have a battery positive ground, can assume it's a 6 volt electrical system.

You may have a cut out or a regulator on the generator. Need to determine which.

Battery fully charged?

Put volt meter on battery. Check battery voltage all switches off and not cranking engine and again when cranking engine with starter. Then with engine started and at mid to high throttle, check voltage at battery again.

While you have the volt meter in hand, disconnect one battery cable. All switches off, check for voltage between battery terminal and cable end.

Re: Cub Farmall will not start

Posted: Wed Sep 18, 2013 5:41 pm
by birddog
David; Jim Becker probably is on the right trail with his reply.

You said the gauge goes to the positive after it starts so as long as it is charging you don't need to polarize it.

A couple other thoughts came to me though.

1st; We are assuming it is a 6 volt, but is it possible when the starter was removed and checked they used 12 volts? If so it may seem fine then, but 6 volts with a load won't do it. Also how did they check it? Just laying on a bench with a battery hooked up, it may seem fine, but again, not with a load.

2nd; If the timing is advanced to far the engine firing will fight the starter, but still once started seem to run good.

Re: Cub Farmall will not start

Posted: Thu Sep 19, 2013 6:49 am
by David D
Eugene wrote:You haven't answered the questions previously posted. Year of tractor and model? But since you have a battery positive ground, can assume it's a 6 volt electrical system.

You may have a cut out or a regulator on the generator. Need to determine which.

Battery fully charged?

Put volt meter on battery. Check battery voltage all switches off and not cranking engine and again when cranking engine with starter. Then with engine started and at mid to high throttle, check voltage at battery again.

While you have the volt meter in hand, disconnect one battery cable. All switches off, check for voltage between battery terminal and cable end.



My tractor is a McCormick Farmall Cub about 1947 -1952. It was my grandfather's. He bought it used back in the early 50's. It is still a 6 volt. Over the years it has been rebuilt once or twice.

Recently I had the tractor worked on, because the last time it was running it would run for about 10 minutes and shut off like it was starving for gas. It would start fine when the battery was charged up and it would start by hand cranking. It had sat in the barn for a year or two.

I asked the repair shop to clean inside the gas tank for rust, put a new carburetor on, repair the lights, and have it read to go. They had it about 4 months. The 1st carburetor send to them was bad and they had issues getting the company to replace it. When it came back it did want to start to unload. They said it had started fine at the shop several time. It sat out side for a while. (It’s a busy place.)

I tried to look and check the wiring. I noticed that there is no junction box with the gauges Out side of some parts changed the wires looked untouched (old). I’m would like to see some pictures of the wiring for the tractor so I know if it is wired correctly.

Re: Cub Farmall will not start

Posted: Thu Sep 19, 2013 8:03 am
by Eugene
David D wrote:I’m would like to see some pictures of the wiring for the tractor so I know if it is wired correctly.
Manuals, top of page. Select the Operator's Manual for to your tractor. In the operator's manual are pictorals of the tractor wiring.

Re: Cub Farmall will not start

Posted: Thu Sep 19, 2013 8:37 am
by Jim Becker
Here are the 2 most common Cub wiring diagrams. They changed from the first to the second in mid-1950. You will need to determine which applies to your tractor.

I still think your problem is a drain on the system when it isn't running, as I said on Wednesday. The drain should be easy to isolate.

Re: Cub Farmall will not start

Posted: Thu Sep 19, 2013 8:47 am
by SONNY
Gotta be in the regulator/cut-out.----also unhook them D--- lights!---had that problem with one of mine and the light circuit was junk,---shorting out entire system!---if the shop had their fingers in the wiring, you are gonna have to go over their work with fine tooth comb to see what they messed up!---THAT is why none of my stuff goes to shops! thanks; sonny