Kubota l2650 Starting Issue

[Whitecat]

My son has a Kubota l2650 that runs absolutely great!! The issue of starting is odd. It will turn over no problem but will not start. Roll it down a small hill and it pop starts right up nice. Not even sure where to begin looking at this issue.

 

[Russell King]

Ok a lot more details will help us to help you…

Tractor is in upstate New York so what ambient temperature is it where the tractor is sitting?
What type of fuel is in tractor (Summer or Winter mix)?
How is he trying to get it started in more details (using the glow plugs correctly and knowing they are actually getting warm?
How old is tractor and is this a new problem that came on suddenly or has it been getting worse over time?
How fast does the starter spin the engine?

First warning is do not use any starting fluid to get it started.

I would start with making sure the glow plugs are in proper operating condition and figure out how to get them to go through two cycles if auto automatic controlled or hold them on for about 20 seconds and then try to start.

After that I would start suspecting bad old fuel or ???

 

[Whitecat]

Ok a lot more details will help us to help you…

Tractor is in upstate New York so what ambient temperature is it where the tractor is sitting?
What type of fuel is in tractor (Summer or Winter mix)?
How is he trying to get it started in more details (using the glow plugs correctly and knowing they are actually getting warm?
How old is tractor and is this a new problem that came on suddenly or has it been getting worse over time?
How fast does the starter spin the engine?

First warning is do not use any starting fluid to get it started.

I would start with making sure the glow plugs are in proper operating condition and figure out how to get them to go through two cycles if auto automatic controlled or hold them on for about 20 seconds and then try to start.

After that I would start suspecting bad old fuel or ???

I believe it’s a 1995 Kubota. As for fuel…tractor is run just about daily so diesel is fresh and current to the season. Temps have been 50’-60’s. When it turns over it spins at a good spin. This has been an ongoing issue for awhile now. He has abandoned trying to start it with key. Always shuts it down on a hill to pop start it. Glow plugs were checked and in working order.
It’s odd that it really starts with very little roll to pop but not when turning over with key.
When it runs…it runs great whether it’s 5 degrees out or 90 degrees. And definitely will not use any starting fluid!!
It’s definitely got me scratching my head.

 

[Russell King]

Does it start easily at operating temperature?

 

[Whitecat]

Does it start easily at operating temperature?

It starts easily cold or hot. Can shut it down after running for an hour or two and pop start it no problem.

 

[North Idaho Wolfman]

Off the top of my head the only thing that makes any sense is that the stop solenoid is being engaged when it's cranking?
Have you checked that ?
In order for that to happen there would be a fault with the stop timer.

 

[Whitecat]

Off the top of my head the only thing that makes any sense is that the stop solenoid is being engaged when it's cranking?
Have you checked that ?
In order for that to happen there would be a fault with the stop timer.

I have not checked that. I will take a look this weekend. Any specifics on checking the stop timer if the solenoid is in abnormal state while cranking it over?

 

[North Idaho Wolfman]

I have not checked that. I will take a look this weekend. Any specifics on checking the stop timer if the solenoid is in abnormal state while cranking it over?

I will just simply need to be replaced if that is what's doing it.

 

[Russell King]

It starts easily cold or hot. Can shut it down after running for an hour or two and pop start it no problem.

But will it crank start when warm?

I think @North Idaho Wolfman is on the right path though so you should follow through on his advice.

 

[number two]

Lift pump?

 

[Pau7220]

Off the top of my head the only thing that makes any sense is that the stop solenoid is being engaged when it's cranking?
Have you checked that ?
In order for that to happen there would be a fault with the stop timer.

It’s a single wire unit on that which pulls the linkage. Unplugging it will be an easy test. The only time it should pull is when the key is turned off for a few seconds.

 

[Whitecat]

I will just simply need to be replaced if that is what's doing it.

I finally got a chance to try and trouble shoot the tractor. Put a new battery in just to make sure cranking speed was good. Inspected the stop solenoid and definitely not the issue. Checked thru all the fuses and the few safety switches and all good. I’m leaning to that maybe the glow plugs need changing and or the engine compression might be a factor. The speed of the pistons is faster when popping in 4th gear that what the starter can produce. After hours of checking as much as I could…. My son popped it off and the rotation of the tires was about 1/4 and it started. I’m not sold on compression but maybe. Thanks to everyone that chimed in to help!! Really appreciate the community here!

 

[North Idaho Wolfman]

I would get a compression test on it.
That will tell you where to go next.

 

[PaulL]

Inspected the stop solenoid and definitely not the issue.

The symptoms really point at that - i.e. something that actively stops it from starting when the starter is cranking. If it otherwise starts easily from a pop start, but won't start with the starter even when warm.....you'd have to suspect something that's tied into the starter cranking rather than things like compression.

Does it start easily with pop starting it? (your comments suggest yes). Can you let it just get a little momentum then pop so it's about the same speed as cranking it is? If the crank speed is the same both popping and cranking, then surely you're looking for an electrical problem?

As I understand it, the way to be 100% certain it's not the stop solenoid is to pull it out, then crank it. And if it starts you have to put the stop solenoid back in so that you can stop it again.