1950 Cub failing to start - shaft not turning

Fri Oct 11, 2013 10:33 am

Hi:

Trying to start this tractor up after leaving it for a week and I can't get it to crank. I hear the starter trying to crank. I had recently put a full charge on the battery so I think it has enough juice to do it. I see the main shaft not turning at all. When I try to turn the fan hub by hand (I don't have a crank, I just pull on the blades of the fan), I can get the fan around on its own shaft but it does NOT turn the belt going to the main shaft.

A few weeks ago we solved my engine seizing issue by lubricating the fan hub and I seem to remember that I moved the fan by hand and it turned the belt too. And when I pulled the starter, even though the fan hub was pretty frozen, I could see the main shaft turning a bit. But now the main shaft does not turn at all when I pull the starter. As part of that fan hub lube, I also ended up squirting a bit of oil into the ports of the generator so that shouldn't be a problem now either. I've checked the engine oil and it is full.

Just to be sure I gave the fan hub some more oil. This time rather than rotate the screw downward to let oil leak out (as per manual instructions), I just put the screw back in. I then watched as oil leaked out the other end of the fan hub (close to where the flywheel for the generator is). Is this right? I'm starting to wonder if this is an oil leak in the fan hub?

Anyway, it won't start and it seems like maybe something is seized again. This has a 6 volt battery. I've wondered if I could try jumping off the car's 12 v battery just to quickly see if a stronger battery will provided the cranking power that might be missing (I've been suspecting that the generator isn't charging the battery because when it was last running for say an hour, the ammeter only showed a level close to 0 - maybe +3 or +5). So I can't tell if the battery is good and just can't turn the frozen shaft, or if the battery has lost its juice just by sitting a week after a full charge.

Re: 1950 Cub failing to start - shaft not turning

Fri Oct 11, 2013 10:42 am

Marshall,
Right now the center of Cub Universe is 60 miles due west of you in Kinderhook, NY at Cecil's CubFest Northeast.
Today, tommorow, and Sunday there is plenty of help available if you were able to get your Cub there.

Have you tried "pop starting" the tractor? On a slight downhill grade put it in 3rd gear, clutch in, ignition switch pulled out. Start coasting and pop the clutch pedal out.

I suppose the woodruff key on the front pulley could be sheared off and that is why nothing is spinning up front even though the starter is turning the engine over.

Peter

Re: 1950 Cub failing to start - shaft not turning

Fri Oct 11, 2013 10:49 am

I agree with Peter! Get your Cub over to Cecil's today or tomorrow and you will get a full assessment of its condition. It's free and you will never find a better deal than that.

Re: 1950 Cub failing to start - shaft not turning

Fri Oct 11, 2013 11:41 am

Battery voltage drop test. Multimeter, DC voltage setting, connect to battery terminals.
Take voltage reading. Tractor out of gear and brakes locked, pull starter rod. Take voltage reading while trying to crank engine over with battery.

Tractor in 3rd gear, rock tractor back ward, then forward. Just in case starter locked into flywheel.

Thinking weak battery and or poor battery cable connections.

Re: 1950 Cub failing to start - shaft not turning

Fri Oct 11, 2013 11:45 am

See if you can borrow a voltmeter and measure the voltage at the battery. have you checked the electrolyte level in the battery? Remove the caps and see what it looks like. If the plates are not covered, your battery is probably bad but you can try adding distilled water and charging it again. Some stores will check a battery at no cost.

Put the tractor in gear and use the rear wheels to rock it with the IGNITION OFF. If the engine turns you are OK. Sometimes the starter gear sticks on the flywheel too, and rocking would probably free that up. Another zero dollar test. make sure you remember to take it out of gear.

You can use 12 volts on the starter but it will fry any lights that you have on.

You had good oil pressure so I don't think this is serious. Look at simple things first.

If the fan hub was seized enough to stall the engine, I don't think oil will bring it back for long. However, if it is moving, it should not be an issue. Extra oil will accomplish nothing but making a mess. Stick to the procedure. Your hub may have been only part of the problem if the battery was weak.

In lock with Eugene. Posting anyway

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 9:03 am

I wasn't able to get to Cubfest. Had other family commitments.

Here's what I was able to do. I used a VOM and found that the voltage dropped a few volts while I pulled starter rod. So I put the battery back on a trickle charger and brought back to full charge. The water levels are covering the plates - levels maybe an inch below caps.

Tried cranking with charged battery. No difference. Just barely a cranking sound. No sign of anything turning. I've tried rocking tractor in 3rd gear to see if it will free anything stuck. No effect.

This battery was effectively starting the tractor 3 weeks ago. It doesn't seem that the battery or cables that could have degraded so rapidly. Lights are disconnected from battery. Could I try jumping off running car just to see if that makes a diff? I'm afraid to roll this down our driveway and perhaps have it fail to jump-start and then I'm left with a dead tractor at the bottom of the driveway further away from service area.

This thing literally went from running well, drove into a parking spot on driveway, shut off for a week, next time I try to start it, I have this problem.

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 9:21 am

marshall wrote: I used a VOM and found that the voltage dropped a few volts while I pulled starter rod.
You need a reading of 4.5 to 5 volts when conducting the voltage drop test.

Remove battery from tractor. Take to auto parts store and have tested.

Clean up the battery cable terminal connections. Also clean up the battery posts, in the event the battery is in good condition.

You can use a 12 volt source to jump start the tractor.

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 9:29 am

Disconnect your 6 volt battery and jump with 12 volt. JUST DON'T KEEP IT ON THERE TO LONG.

Have you taken the starter off and put power to the starter.

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 9:31 am

My 2 cents. Not enough current getting to the starter, bad battery, weak connection, or a bad starter. Jumping it at the starter (better to use 6 volt if possible, 12 volt will work but a weak starter will spin ok on 12 volts) may help determine which is the problem, if any of the above. If the starter turns the engine when jumping it, bad connections somewhere or a weak battery.

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 9:54 am

Take the starter off and use a pry bar to turn the flywheel by CAREFULLY prying against the teeth you see in the hole.

You should be able to get the engine to turn with the tractor in 3rd gear by rocking it back and forth.

If you can turn the fan hub by hand it's not the fan this time. Frankly I don't think it was the fan last time. Your fan belt isn't tight enough to stop the engine.

I hate to say it, but be prepared for the possibility that your engine is really and truly seized. It sounds like maybe the person who "rebuilt" the engine cut some corners. Worse, they may have known about the problem and that's why the tractor was for sale.

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 11:04 am

marshall wrote: So I can't tell if the battery is good and just can't turn the frozen shaft, or if the battery has lost its juice just by sitting a week after a full charge.
I suggest you have someone come by check it out. Anyone you know nearby that could help you out?

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 11:37 am

Is the PTO engaged?

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 12:34 pm

If the crank pulley doesn't turn when you turn the fan, I don't think it's the starter. You should be able to turn the engine over by pulling on the fan blades.

Several posters have suggested that you put it in third gear and try rocking it to see if the engine turns. Have you tried this yet? Or Matt's suggestion of removing the starter and trying to turn the flywheel with a prybar?

Before you accuse the starter, make sure that the engine is free. Even a BSN starter with a BSN battery won't turn an engine that is seized or nearly so.

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 12:50 pm

bythepond88 wrote:Several posters have suggested that you put it in third gear and try rocking it to see if the engine turns. Have you tried this yet?

marshall wrote:I've tried rocking tractor in 3rd gear to see if it will free anything stuck.
Question is, did the engine turn over when you rocked the tractor in 3rd gear? You only need to roll the tractor about a foot in either direction to observe the fan blades moving.

Re: 1950 Cub failing to start - shaft not turning

Wed Oct 16, 2013 1:39 pm

Found this very thing with a friend's tractor here in Pittsburgh. He thought it was the starter, and had it checked over twice. I brought my starter off of Merlin to try and had the same results. Then I tried the hand crank, and the tractor was TIGHT TIGHT TIGHT, but would turn. In our case, we got lucky...re-primed the oil pump and the engine loosened up. Since you said that you parked it in its spot and now it won't turn, do as Eugene (and others) have suggested to make sure that the engine will turn when in 3rd gear.

Hoping that you have positive results and that this is an easy fix...

Mike