B2400 Starting Issues

[EdJohn]

Hello, new to this forum, thanks in advance for any help.

This tractor is generally very good shape with 1400 hrs.

Developed a starting issue this winter and can't understand what is going on.

All of a sudden it won't turn over. It's like the starter is trying but can't move the motor. I went through all the basic starting items cleaned the terminals, cleaned the ground to the frame, etc., replaced 4 year old battery no changes. BTW... I did that fix years ago where you put the John Deere relay on there and it worked beautifully. In fact since this problem was similar I just replaced that same relay with a new part in the event that it went bad. No change. Tried jumping from my car, no change.

So here is where it gets interesting. Testing to see if there was some issue where the motor literally won't turn, I rotated the motor a little bit by tensioning the fan belt and the rotating the fan and it appeared to rotate fine without resistance. Right after that, just for the heck of it, I test to start it and whala, it starts up just fine with no issues. I then let it run for ten minutes and shut it down. I then go to start it again and back to same issue, struggles to turn the motor at all. I then go back and rotate the motor a small amount like before and then once again it starts fine.

I'm out of my depth on this one, I have no idea what is going on.

Thanks for any suggestions.

JC

 

[PoTreeBoy]

Hello, new to this forum, thanks in advance for any help.

This tractor is generally very good shape with 1400 hrs.

Developed a starting issue this winter and can't understand what is going on.

All of a sudden it won't turn over. It's like the starter is trying but can't move the motor. I went through all the basic starting items cleaned the terminals, cleaned the ground to the frame, etc., replaced 4 year old battery no changes. BTW... I did that fix years ago where you put the John Deere relay on there and it worked beautifully. In fact since this problem was similar I just replaced that same relay with a new part in the event that it went bad. No change. Tried jumping from my car, no change.

So here is where it gets interesting. Testing to see if there was some issue where the motor literally won't turn, I rotated the motor a little bit by tensioning the fan belt and the rotating the fan and it appeared to rotate fine without resistance. Right after that, just for the heck of it, I test to start it and whala, it starts up just fine with no issues. I then let it run for ten minutes and shut it down. I then go to start it again and back to same issue, struggles to turn the motor at all. I then go back and rotate the motor a small amount like before and then once again it starts fine.

I'm out of my depth on this one, I have no idea what is going on.

Thanks for any suggestions.

JC

Im not saying starter - yet.
Put your voltmeter leads on the large starter post and the body of the starter. It should read about 12 volts. Now, try to start. What does the voltmeter read? If it stays at 10 volts or so, you probably have a bad starter/solenoid. If it goes to about 8 or below, you have a loose connection, bad cable, etc.

 

[EdJohn]

Thanks Po

So I tried this and of course it is starting right up now so I don't know if that invalidates the test.

It looks like I get 12.x reading just with key on and then if I go to start it, it looks like it is 9.x but like I said the damn thing started right up both times I tried.

I'm still very puzzled how manually rotating the motor a small amount somehow resolved it before.

 

[PoTreeBoy]

Thanks Po

So I tried this and of course it is starting right up now so I don't know if that invalidates the test.

It looks like I get 12.x reading just with key on and then if I go to start it, it looks like it is 9.x but like I said the damn thing started right up both times I tried.

I'm still very puzzled how manually rotating the motor a small amount somehow resolved it before.

Well, now you have a baseline. Next time it won't crank, re-test.
You could also use the old 'fix' - tap it with a wrench or hammer.

 

[Dave_eng]

When the engine is stopping, I would suggest it stops as one of more pistons are coming up on their compression stroke.

A small turn by hand my get the cylinder sequence just past the point of most resistance to rotation.

I think it is time for you to try jumping the starter to help narrow down where the source of the starting hesitancy lies.

Jumping the starter is dangerous because every safety is by passed and you can get run over. Best to have someone in the seat with the brakes applied.

Expect a small spark as you make the jump connection. The engine should crank immediately unless there are problems with the starter or with the electrical supply to the starter or battery.

Dave