Kubuta KX41 Starter (intermittant issue)

[aesmith]

Hi,
This has happened twice now, the starter gives no response whatsoever when the key is operated, not click or other sound. The instrument lights dim about as much as I'd expect with the starter running, but would not quite swear it's exactly the same. Unfortunately I didn't measure the current draw on either occasion. First time I suspected the battery and battery leads as both were quite rough, although I couldn't actually see any issue and disconnecting/reconnecting leads didn't help. Finally I connected a battery which had been sitting on charge and it started up fine. So I was thinking along the lines of the battery just not having enough oomph to trigger the starter into life.

Since then I've replaced the battery and also fitted nice new battery leads and it's been fine. Then on Saturday the same symptoms. This time the battery had been on a trickle charge so was fully charged.

I removed the starter and has a little poke around. With the end cover off I could feel the solenoid free to move, and unbolting the motor I found I could turn that as well, although felt quite stiff. Put back to together and refitted, it works fine again.

First time was restarting after a lunch break. Second time the digger hadn't been used for a while.

Any ideas? I am thinking I may just replace the starter as they're not that expensive, and we're completely immobilised if the engine won't start. Even if I do that I'd like to fix the old one as well.

Thanks, Tony S

[ianoz]

possibly bushes worn out in starter . Had a JCB 4CX starter do the same .

[aesmith]

Thanks. Did you mean brushes, or bushes? I can check both of course. My thinking is if this was an issue with the motor, I'd expect to hear the solenoid move. I know something's drawing power because the lights dim, and the motor doesn't get switched on until the solenoid has completed it's travel, so that sounds like the solenoid is drawing current but not moving. Yet when I took the cover off it seemed completely free to move. So I'm thinking that the actual act of part dismantling it may have freed whatever was sticking.

[ianoz]

The auto electrician that fixed it said the bushes were worn and it was poling out ..

[aesmith]

So 18 months on I've not got to the bottom of this. I caved in and replaced the starter with one from Ebay (a mistake), that worked OK but made a lot more metal on metal noise than the original.

Over a year or so the Ebay motor got more and more noisy and more and more sluggish, acting as if the battery was flat. In the end I swapped back to the old one and that confirmed it was the Ebay starter at fault and not battery or wiring. Now six months on the digger hasn't been used for a while, and the starter didn't work. Swapped the Ebay one back in and it reluctantly fired up.

So looking for ideas here. Unless I have some sort of brain wave I've almost decided to get another new starter this time from LS Engineering the guys I get Stihl parts from. Hopefully better than some random Ebay seller. Any other suggestions for trustworthy sources?

In addition I'd really like to see if I can fix the original, it's been in bits again today and bushes and bearings are fine, I gave the contacts closed by the solenoid a good clean, and testing on the bench it works fine. I would very much appreciate any pointers.

Thanks, Tony S

[aesmith]

Change of plan, LS starter only has 6 months warranty. Back to Ebay I guess.

[Muz]

Change of plan, LS starter only has 6 months warranty. Back to Ebay I guess.

I have a guy in Glasgow that re conditions them .. plus there are other sources of supply .. some times they cant be re conditioned of course, but either of these options will be cheaper than oem, and his stuff will have a years warranty I think

[aesmith]

Thanks. I am still trying to get to the bottom of the actual fault. Two more theories, one is that apparently some starters are sensitive to voltage or power on the solenoid, so via the wiring etc it may be marginal if it has enough "oomph" for the solenoid to complete it's travel. Could of things I could try when it's next failed, (1) measure voltage drop between battery + and solenoid connector and (2) a jump lead from solenoid connector to the 8mm stud to try full voltage.

Second one is that the teeth aren't meshing so travel is getting blocked. I'm not sure on these motors whether the motor turns at low power to ensure it can mesh (I think Lucas do that) or whether the bevels on the teeth are designed to push past. If so then maybe stickiness in the pinion rotation could be stopping that happening.

We do have a good auto electrical place but it's in the city and now I don't work there it would mean a 60 mile round trip to drop it off, and another to collect.

Annoyingly none of the traders I've seen so far will confirm their new starter will definitely fit either based on engine type (D1105-BH) or machine KX41. They all want original part numbers to cross-reference, and even our original starter looks like an after market replacement and has nothing like the sort of reference numbers quoted.

I wonder if there's a way to find the Kubota part number for the originally fitted starter? Or for Kubota's current replacement?

[Muz]

I wonder if there's a way to find the Kubota part number for the originally fitted starter? Or for Kubota's current replacement?

I'll see if I've got any old books and find a number .. is it the first version KX41 ?

[aesmith]

Thanks, yes it's the original KX41 not -2 or -3.

[Muz]

Thanks, yes it's the original KX41 not -2 or -3.

Ive had a look and its the only parts book I dont have despite owning several of these at one time.. ive got the number for a kx 36 but the 41 had a slightly bigger engine, Your best bet is just to phone a dealer

[aesmith]

Thanks. I've made a little progress. Initially some dead ends as suppliers who list starters even as "all models" of D1105 say their starter is not compatible with D1105-BH. Maybe it's just easier for them to say no if it's not explicitly listed. Do you think there's any real compatibility issues between different D1105 versions? For example if it's listed as compatible with "D1105" "D1105-E" and "D1105-T" is it still possible it won't fit a D1105-BH?

Then I found a PDF parts list, its from the US and calls the digger KX41H I don't know if that's significant. This gives two parts 19269-63010 for earlier and later interchangeable 19269-63012. Searching on that second part finds a couple of suppliers. LS Engineers cross reference a different part 19269-63013 but also say it replaces 19269-63010, 19269-63011 and 19269-63012. This might be the 1.2kW vs 1.4kW that I've seen mentioned by some suppliers. So it looks like there are some options, although none of the 5 year warranty parts will promise compatibility.

Flywheel Starter 2 Screenshot_34.png
As a separate job I've dismantled the crap Ebay starter to see if there's any mechanical reason for it getting weaker and weaker. I can't see one, all the parts move freely and look as new.

Next time it gives trouble I'll do the same with the original, but I can't be bothered to take it off again when I don't yet need to.

[Muz]

Thanks. I've made a little progress. Initially some dead ends as suppliers who list starters even as "all models" of D1105 say their starter is not compatible with D1105-BH. Maybe it's just easier for them to say no if it's not explicitly listed. Do you think there's any real compatibility issues between different D1105 versions? For example if it's listed as compatible with "D1105" "D1105-E" and "D1105-T" is it still possible it won't fit a D1105-BH?

Then I found a PDF parts list, its from the US and calls the digger KX41H I don't know if that's significant. This gives two parts 19269-63010 for earlier and later interchangeable 19269-63012. Searching on that second part finds a couple of suppliers. LS Engineers cross reference a different part 19269-63013 but also say it replaces 19269-63010, 19269-63011 and 19269-63012. This might be the 1.2kW vs 1.4kW that I've seen mentioned by some suppliers. So it looks like there are some options, although none of the 5 year warranty parts will promise compatibility.

Flywheel Starter 2 Screenshot_34.png
As a separate job I've dismantled the crap Ebay starter to see if there's any mechanical reason for it getting weaker and weaker. I can't see one, all the parts move freely and look as new.

Next time it gives trouble I'll do the same with the original, but I can't be bothered to take it off again when I don't yet need to.

Both the KX36 No's start '16' so theres no comparison there. One thing .. I had one once that had the main wire going to the starter chaff through on a chassis rail.. have you made sure the supply to the starter is good and well earthed ? and failure here would give the problems you describe

[aesmith]

Thanks. I replaced the battery cables as the connectors were damaged and poor quality. So I replaced them and used plastic trunking to play safe. Earth goes to the engine block, just under the starter. So that all looks OK to me, unless it would be worth moving the earth to one of the starter bolts (means changing the terminal) or a jumper from the earth stud to the starter bolt.