Re: Farmall Cub Engine Rebuild

Wed Dec 19, 2012 10:58 am

I am confused here, is it locking up or shutting down? Locking up tells me an instant stop with no winding down. If it is what I think it may sound like something in the electrical system like a bad wiring connection shorting out, bad coil, condencer. I have replaced a lot of coils and that has solved my problems in instances like what your describing.

Take it a step at a time and maybe back track and rethink what you did, I'm sure you'll figure it out in no time.

My thoughts,

Good luck

Re: Farmall Cub Engine Rebuild

Wed Dec 19, 2012 2:33 pm

jim turner wrote:Rick in his first post he said he disconnected the pump

He said
we disconected the pump and put a plate on it

If that means took off the manifold, left the pump installed and put a plate over the openings on the pump, it could be deadheading and on the verge of destroying the pump or valve train.

edit: fixed typo

Re: Farmall Cub Engine Rebuild

Wed Dec 19, 2012 3:14 pm

Jim you are absolutely right, I assumed he meant he removed the pump and put a plste whee the pump was mounted on the engine. He needs to be more clear if anyone is too help.

Re: Farmall Cub Engine Rebuild

Thu Dec 20, 2012 9:10 pm

Is your fan pulley free?

Re: Farmall Cub Engine Rebuild

Fri Dec 21, 2012 3:49 pm

Hydraulic pump is off, bypass plate installed. Start engine runs great on idel. Go to about half throttle and engine runs good for a few minutes then it sounds as if it is bogging down or if it were in a hard pull. The engine suddenly stops you can here the fan belt squeel as the fan turns just a bit. When this happens I can reach down turn the engine by hand or pull the starter and it starts. I wished I could expain more. It has new points plugs condenser coil. Thanks for the help. Mark C

Re: Farmall Cub Engine Rebuild

Fri Dec 21, 2012 3:56 pm

Belt squealing, fan locking up or generator locking up. Remove the belts and see what it does, and oil the fan, there is a screw in the fan you take out and squirt oil in it turn the fan a few times then put the hole down to bottom and let the excess oil run out , replace the screw.
Boss

Re: Farmall Cub Engine Rebuild

Fri Dec 21, 2012 5:57 pm

zekie1997 wrote:Hydraulic pump is off, bypass plate installed. Start engine runs great on idel. Go to about half throttle and engine runs good for a few minutes then it sounds as if it is bogging down or if it were in a hard pull. The engine suddenly stops you can here the fan belt squeel as the fan turns just a bit. When this happens I can reach down turn the engine by hand or pull the starter and it starts. I wished I could expain more. It has new points plugs condenser coil. Thanks for the help. Mark C


Marc:

If you have a digital camera take a movie of what is happening. Once the guys can hear what is happening they should be able to figure out what the problem is. You have some great diagnostic guys trying to help .. so give em a audio/visual help if you can.

Re: Farmall Cub Engine Rebuild

Fri Dec 21, 2012 7:58 pm

My money is on Boss Hog's analysis. The symptoms are classic for a dry fan hub bearing. My guess is once you replenish the oil in the hub, the problem will be solved. When the bearing is cold, it will turn even without oil, but after a few revolutions heat builds up and the bearing seizes on the shaft. Check the manual to make sure you understand how to oil the hub properly.

Re: Farmall Cub Engine Rebuild

Fri Dec 21, 2012 9:40 pm

challenger wrote:My money is on Boss Hog's analysis. The symptoms are classic for a dry fan hub bearing. My guess is once you replenish the oil in the hub, the problem will be solved. When the bearing is cold, it will turn even without oil, but after a few revolutions heat builds up and the bearing seizes on the shaft. Check the manual to make sure you understand how to oil the hub properly.


Manuals are at the top of this page.

Re: Farmall Cub Engine Rebuild

Fri Dec 21, 2012 10:58 pm

Sorry about all the confusion here. I stated it this after noon and it ran on idel for 2 hours sound great no skip no sputter purs like a kitten. When I give it throttle it sounds like the engine starts laboring and and I noticed a clatter when it was getting ready to stall. I am going to check valves again and then move to the governor and distibute. It has new fan not any problems with that. I just hope I dont have to take the engine back down. Thanks Mark c. I will try to get digital camara if I cant get her going.

Re: Farmall Cub Engine Rebuild

Fri Dec 21, 2012 11:14 pm

zekie1997 wrote: It has new fan not any problems with that.

Do you mean just fan blade or does it also have a new fan hub assembly? If you are still using the old fan hub assembly and there is no oil in it you can have the problem Boss Hog said.

zekie1997 wrote: you can here the fan belt squeel as the fan turns just a bit.

If the engine stops first it is unlikely the blade would free spin enough to cause the squeel. If the fan hub starts to lock up the belts will squeel for a second befor the engine stops. Go back and double check that hub before taking the engine down.

A lot of Cubs with supposedly locked up engines have been found and the hub turned out to be the problem and not the engine.

Re: Farmall Cub Engine Rebuild

Sun Dec 23, 2012 3:03 pm

And that's why I asked about the fan pulley being free, as I was one that started on an engine teardown when it was a locked up fan pulley that was killing the engine....but I stopped at the main bearing inspection....

I would do as others suggest - unhook everything, including the fan and genny and see what you get.

Oil pressure 'normal'? - pegged on the gage is normal, but you can't tell if you're getting 150psi or 50 psi. 200psi gages are $5 at Tractor Supply while 100 psi gages are double that....
Oil relief valve working right?

Too much or not enough lube will cause similar problems. Any funky cross drilled lube holes that got plugged by accident during the rebuild? or left out?