D1105 Starter Issues

aesmith · Feb 3, 2023

Hi,

The engine is a D1105-BH fitted to a KX41 digger rather than to a tractor, in case that makes a difference.

The starter intermittantly doesn't work, the solenoid draws power but doesn't move or doesn't energise the motor for some reason. First time it did this was after a lunch break, so the machine had been in use up to around an hour before. At that time I fiddled around with connections and batteries etc and suddenly it worked. Since then I've fitted a new battery and replaced the battery cables as well because they were a bit rough.

All was well for a while then it did it again, this time I took the starter off, opened it up and everything seemed OK. Refitted and it worked again.

I don't know how many time this cycle was repeated but I got fed up and bought a new starter from Ebay. At first all was well but the Ebay starter gradually got sick over maybe a year, becoming noisier and really sluggish as if the battery was weak. I ended up refitting the old one.

Then two days ago it wouldn't start, same symptoms. Because I really needed it I refitted the sick Ebay starter and got fired up. Checked out the original, opened it up and everything looked fine, tested on the bench also fine. I wish I'd tested on the bench before opening it up, will try to remember next time.

I intend to get a decent quality replacement, I'm fed up with this. The problem is finding one that's not rubbish.

But I would also really like to understand what could be going on with the original. It's clearly better quality and I feel I ought to be able to get it fixed even if just as a spare.

Any ideas would be appreciated.

Thanks, Tony S

Eagle1 · Feb 3, 2023

On my bota the starter solenoid moves the spur gear into place on the flywheel as it becomes FULLY extended the contacts on the other end close and the motor turns. Now if the spur gear hits the flywheel gears and does not jam its way into place the contacts will never close. Every now an them I have to bump the flywheel to allow the gears to mesh. I just use the first stick on hand and poke the gear teeth on the flywheel.
You may want to check that spur gear is not hitting the flywheel gear when it tries to start. No idea why it would stop just in the wrong place but it does and never does it unless I'm in middle of something or far from the shop. Never seems to do it when I'm near tools. BTW new starter did not really help the problem for long, lubricating the spur gear shaft seems to help a bit but it comes back whenever you have no time or patience for it.

aesmith · Feb 3, 2023

Thanks, that's interesting. The only pre-engaged starter I looked at in detail before this, actually energised the motor a little to avoid exactly that. On that starter the solenoid was in series with the motor so it got a little bit of power enough to gently turn the shaft to help in engage. Then as you say once fully meshed the contacts close and the motor goes full power. Maybe the Kubota starter doesn't do that, I may be able to test on the bench.

JWR · Feb 3, 2023

I do not know the whole story as to what is going on with these starters but I have a B2150 4cyl Kubota that sometimes will not start -- just like you say will not turnover. Does not even make any noise. I have found that if I take a fairly heavy metal rod (such as a socket set extension rod) and tap it end-first into the body of the starter it will then start OK. Sometimes have to tap the rod lightly with a small hammer to get a stronger impact. Very possibly the small gear (normally moved outward by the solenoid) is hanging up for some reason or needs lubrication. Others have suggested that the starter itself has stopped at a rotation angle where the contacts are not energizing it (but that make no sense to me because I have 3 B2150s and the other 2 never do it...) So I DO NOT KNOW the cause but suggest you try tapping on the starter motor with a heavy piece of metal at the times when it won't turn -- see if that works.

On smaller Kubotas (and John Deere and others) there is a well known issue where the full 12v does not make it to the solenoid dues to voltage drops between the battery and the solenoid. No matter the condition of the battery a charger puts out MORE than 12v and may over come those losses so you can try connecting a battery charger and see if that causes it to start.

RjCorazza · Feb 3, 2023

On my D1005 engines I had similar starter problems. I don't know how similar these starters are to the ones on a d1105 , but replacing the starter solenoid would get mine working for a season or so. The permanent fix was to wire up a relay that provides the 12 volts to the solenoid straight from the battery post on the starter.
It's a quick job, and costs maybe $20 in parts... or less.

Eagle1 · Feb 3, 2023

Done that on a couple of Zturns with their convoluted safety switches.

JWR · Feb 3, 2023

RjCorazza said:
On my D1005 engines I had similar starter problems. I don't know how similar these starters are to the ones on a d1105 , but replacing the starter solenoid would get mine working for a season or so. The permanent fix was to wire up a relay that provides the 12 volts to the solenoid straight from the battery post on the starter.
It's a quick job, and costs maybe $20 in parts... or less.

Yeah, that is what I was talking about with my smaller BX2200 Kubota. Deere sells a kit for putting an extra relay in that conveys the 12v direct from the battery to the solenoid bypassing all the voltage drops of the various safety interlocks. A Kubota dealer put that same sort of kit on my BX2200 which they called a "hard start kit" but charged $60. I'm sure an electrically knowledgeable person (which I should be but an old and lazy) could do it like you say for $20. HOWEVER, that may not be the OP's problem. He may have some other problem with the starter.

aesmith · Feb 3, 2023

Thanks, keep them coming please.

On these starters I don't think the solenoid is a replaceable part, they're sort of round the other way from most starters with the motor piggy backed onto the solenoid. See photo, the solenoid is the lower module with the terminal stud, the motor is mounted above and drives via an reduction gear.

I can rig up something to test that voltage-to-the-solenoid idea, a heavy cable with a push button that I can temporarily rig up next time it's in a sulk. It might actually explain why messing around with different batteries persuaded it to play the game in the first instance. Not so much the last time as I left the battery on charge overnight and it didn't work the next morning.

RjCorazza · Feb 3, 2023

JWR said:
Yeah, that is what I was talking about with my smaller BX2200 Kubota. Deere sells a kit for putting an extra relay in that conveys the 12v direct from the battery to the solenoid bypassing all the voltage drops of the various safety interlocks. A Kubota dealer put that same sort of kit on my BX2200 which they called a "hard start kit" but charged $60. I'm sure an electrically knowledgeable person (which I should be but an old and lazy) could do it like you say for $20. HOWEVER, that may not be the OP's problem. He may have some other problem with the starter.

In replying, I meant to mention your statement and expand a little - then forgot. The OP'S problem description just sounds SOoo much like what I went through with starters, I can't imagine the relay won't fix his problem.
Hopefully he gets it straightened out.