L2550 - Hard starting at all temps

ruger1980

Active member

Equipment
L4310 w/La682, L225
Oct 25, 2020
424
148
43
CNY

ruger1980

Active member

Equipment
L4310 w/La682, L225
Oct 25, 2020
424
148
43
CNY

GreensvilleJay

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Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
12,008
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Greensville,Ontario,Canada
slow spinning, maybe due to LOW battery voltage and current capability.

8.5 volts on glowplugs gets about 50 amps to them ( 8.5 / .16) ,may not be getting hot enough ?

I'd expect 10 volts on the GPs and that'd get 20 amps PER GP.. (so 60 amps just to heat them..)
I wonder what the OM/WSM says as to 'specs' ?
 
Last edited:

Stinger23

Member

Equipment
L2550 w/LA400 Loader
Jan 9, 2025
34
3
8
Basehor KS
12.6v or higher is considered fully charged and that's right where mine is so it shouldn't be low battery voltage, though it could be low voltage at the starter due to a bad connection somewhere. That's what I'll test next time I'm near the tractor.
 

ruger1980

Active member

Equipment
L4310 w/La682, L225
Oct 25, 2020
424
148
43
CNY
One more question, does it start better if the throttle is at full fuel? If so there could be an issue with the start spring in the governor assembly.
 

Stinger23

Member

Equipment
L2550 w/LA400 Loader
Jan 9, 2025
34
3
8
Basehor KS
One more question, does it start better if the throttle is at full fuel? If so there could be an issue with the start spring in the governor assembly.
It starts better with some throttle for sure. I don't honestly think it would ever start if the throttle was at idle, even in the summer. I give it about a 30% throttle for it to start in the summer. In the winter I've only started it three or four times so I've not figured out what works best yet, but I've certainly given it a lot of throttle to get it to start, not necessarily full throttle.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
Address the glow plug circuit before you even bother with the compression.
Which by the sound of it cranking is not an issue.

Contrary to @ruger1980 statement, a Kubota requires the glow plugs to work properly for it to fire when cold.
The glow plug circuit works in preheat and while cranking.
I don't have to preheat my glow plugs unless it's in the 20's but if I do, it certainly starts faster.

The chances of a start spring being damaged is really rare, but could happen.
You will have to pull the stop cover and the throttle cover in order to inspect it.
If you go down that path let me know and I'll explain better.
 

GreensvilleJay

Well-known member

Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
12,008
5,207
113
Greensville,Ontario,Canada
12.6v or higher is considered fully charged and that's right where mine is so it shouldn't be low battery voltage, though it could be low voltage at the starter due to a bad connection somewhere. That's what I'll test next time I'm near the tractor.
in post #60....
G2 Black/White: 0, 0, 8.4, 7.7

G2 is only 8.4 volts NOT 12.6. BTW 12.6 would usually be at 'room temperature of 70*F'.....

I'm assuming 8.4 is glow plug voltage, but there will be IIR drop between switch and actual glow plugs.

What's rating for the battery ( CCA ) ,age and 'state of charge' ?

Even at 8.4 volts, the 3 glowplugs draw 50 amps out of the battery, so doing that for any length of time , the battery 'terminal' voltage goes down and then stuff that needs 12 volts doesn't get 12 and won't operate properly. It's a vicious downward spiral.

FWIW I needed a second BIG battery on my forklift JUST for the air intake heater( glow plug on steroids ).Without it, starter turned slower after 30 seconds of preheat vs no preheat.

I'd like to see a solid 10 volts at the glow plugs after 30 seconds of preheat'. The experts will know what's 'acceptable'.