BX starter getting weak

dlsmith

Well-known member
Lifetime Member

Equipment
BX2230, LA211
Nov 15, 2018
1,235
789
113
Goshen, IN
The starter on my BX2230 has been getting progressively weaker. A couple of times it wouldn't crank at first and after trying it several times got it to crank and start the engine. Now, when I turn the key to the start position, noting happens for a seconds or so, then it starts cranking but slowly. So far it cranks fast enough to start the engine, but I'm not going to wait until it fails completely.

Has anyone had any luck with local rebuilders repairing these Denso starters?
If so, I would like to try that before I shell out over $400 for a Kubota starter.

There are aftermarket starters on Amazon for around $100. has anyone tried one of those?

And no, it's not the battery, cables or connections, I have checked all those and they are good.
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,781
2,965
113
North of Pittsburgh PA
Sounds like the brushes in the starter motor have worn short.

Perhaps you should check/replace them...
 

dlsmith

Well-known member
Lifetime Member

Equipment
BX2230, LA211
Nov 15, 2018
1,235
789
113
Goshen, IN
Sounds like the brushes in the starter motor have worn short.

Perhaps you should check/replace them...
That's kind of what I was thinking. I'll pull it off and take a look at it this afternoon and report back,

Thanks.
 

RCW

Well-known member
Lifetime Member

Equipment
BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
9,151
5,234
113
Chenango County, NY
Holy smokes a $400 starter!?!?
I have a BX also, guess I would try a rebuild too.
Be interested to see how you make out.


Sent from my iPhone using Tapatalk
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
555
83
USA
Probably the OEM price. Flea Bay is loaded with starters, much cheaper but probably Chinesium in manufacture though Kubby starters will also be made offshore.
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
555
83
USA
Not much to puke in a starter except the Bendix and the brushes. I'd start by making doubly sure the terminals are clean and bright and apply some di-electric grease to insure they stay that way.

Sounds to me like a resistance issue caused by terminal corrosion.
 

Roadworthy

Well-known member
Lifetime Member

Equipment
L2501 HST
Aug 17, 2019
1,649
526
113
Benton City, WA
Be sure the starter mounting bolts are tight as well as the power terminal. The mounting bolts complete the circuit to ground. Other than that, yep, check the brushes.
 

dlsmith

Well-known member
Lifetime Member

Equipment
BX2230, LA211
Nov 15, 2018
1,235
789
113
Goshen, IN
So, I took the starter off, pretty easy after you remove the engine cowl. First thing I checked was the solenoid contactor, and while the contact plate looked pretty good, and I have seen some with holes burned completely through, there was a little tit of copper on the contact that goes to the starter motor. You can see quite plainly in the third picture. That would definitely would be a high resistance point with all the current going through it. I cleaned up the contact plate, scraped the little piece of copper off the motor contact and cleaned up both contacts so they will make better contact.

I pulled the end cover off the motor and the brushes look pretty good, probably 3/8" long or so, the brush holder doesn't look like it had been hot, and the armature looks fine also
.
I put the starter back together and put it back on the tractor, and now it does turn the engine over faster that it did before. It doesn't hesitate before it starts cranking like it did before.

We'll see if my fix lasts, or if I need to pull it I may put in new brushes and have the armature cleaned up. Looking at the parts manual, it doesn't appear that the brushes are sold separately, but you have the buy the complete brush holder assembly which is over $40 at Messicks. For another $45 I can buy an entire starter on Amazon.

I'm certainly not going to buy a $400 starter from Kubota.
 

Attachments

SDT

Well-known member

Equipment
multiple and various
Apr 15, 2018
3,255
1,042
113
SE, IN
The starter on my BX2230 has been getting progressively weaker. A couple of times it wouldn't crank at first and after trying it several times got it to crank and start the engine. Now, when I turn the key to the start position, noting happens for a seconds or so, then it starts cranking but slowly. So far it cranks fast enough to start the engine, but I'm not going to wait until it fails completely.

Has anyone had any luck with local rebuilders repairing these Denso starters?
If so, I would like to try that before I shell out over $400 for a Kubota starter.

There are aftermarket starters on Amazon for around $100. has anyone tried one of those?

And no, it's not the battery, cables or connections, I have checked all those and they are good.
Are you CERTAIN that it's not the battery or cables?

If so, you can buy aftermarket starters on line. I bought a new starter/solenoid assembly for my B1750 for $72.00 delivered about a month ago.

SDT
 

dlsmith

Well-known member
Lifetime Member

Equipment
BX2230, LA211
Nov 15, 2018
1,235
789
113
Goshen, IN
Are you CERTAIN that it's not the battery or cables?

If so, you can buy aftermarket starters on line. I bought a new starter/solenoid assembly for my B1750 for $72.00 delivered about a month ago.

SDT
Yep, I pulled the battery and put in a new one I had on hand for my Chevy Nova, and it didn't crank any faster. I also took both the hot and ground cables off on both ends, cleaned them and reinstalled them. No difference.
Kinda leaves the starter as the culprit.
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,207
1,893
113
Mid, South, USA
The right way to diagnose it is with a voltage test

Or you can throw parts at it-which might work.

Those starters aren't known to fail often. Contrary actually.
 

dlsmith

Well-known member
Lifetime Member

Equipment
BX2230, LA211
Nov 15, 2018
1,235
789
113
Goshen, IN
Took the starter off this morning and took it to an Amish shop that does a lot of lawn, garden and farm equipment starters, generators and alternators. He pulled it apart and when he checked the armature, he found it was shorted or open on one of the windings. He does a lot of Kubota work and had a rebuilt one on the shelf. He also said the Denso starters are usually pretty good, but every now and then he gets a bad one, usually from someone cranking the engine for a long time, like if the glow plugs aren't working. I guess it's a common starter on a lot of small equipment.

Paid $75 for the rebuilt unit with a 2 year warranty.

Took it back and installed it, and holy cow, it has never cranked that fast before! I always thought it cranked little slow, but it always started.

So, mystery is finally solved.

Thanks for all the suggestions.
 

200mph

Well-known member

Equipment
L4740-3 Cab, FEL, Fnt Snow Blower L2185, LP Finish Mower, LP Rotary Mower
Mar 3, 2017
1,228
61
48
PA
Thanks for reporting back on what the root cause was and glad your problem is fixed.