B7500 start problem

Russell King

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Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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Austin, Texas
As stated by @North Idaho Wolfman the black smoke indicates over fueling. I would do something with the injectors at this point I guess…
1) inspect the spray pattern
2) have injectors tested and rebuilt
3) replace injectors with new OEM injectors

Hopefully you can wait on more experienced advice and see if there is any consensus. I just don’t see how they would just fail in a sudden manner.

Since you were using it in a firefighting mode can you recall anything that could have harmed the engine other than running low on fuel? Was it thick smoke being sucked into the engine? What did the air filter look like when replaced? Was there anything in the smoke that could have effected the combustion chamber?

I am guessing something may be damaged but I believe your tractor is old enough to be purely mechanical on the fuel injection system so can’t really see how the fire would damage the injection system.

Did you cut open the fuel filter(s) to see if there was anything that was suspicious inside?
 

LawEd

New member

Equipment
B7500HST
Jun 5, 2025
15
3
3
Alberta
As stated by @North Idaho Wolfman the black smoke indicates over fueling. I would do something with the injectors at this point I guess…
1) inspect the spray pattern
2) have injectors tested and rebuilt
3) replace injectors with new OEM injectors

Hopefully you can wait on more experienced advice and see if there is any consensus. I just don’t see how they would just fail in a sudden manner.

Since you were using it in a firefighting mode can you recall anything that could have harmed the engine other than running low on fuel? Was it thick smoke being sucked into the engine? What did the air filter look like when replaced? Was there anything in the smoke that could have effected the combustion chamber?

I am guessing something may be damaged but I believe your tractor is old enough to be purely mechanical on the fuel injection system so can’t really see how the fire would damage the injection system.

Did you cut open the fuel filter(s) to see if there was anything that was suspicious inside?
As stated by @North Idaho Wolfman the black smoke indicates over fueling. I would do something with the injectors at this point I guess…
1) inspect the spray pattern
2) have injectors tested and rebuilt
3) replace injectors with new OEM injectors

Hopefully you can wait on more experienced advice and see if there is any consensus. I just don’t see how they would just fail in a sudden manner.

Since you were using it in a firefighting mode can you recall anything that could have harmed the engine other than running low on fuel? Was it thick smoke being sucked into the engine? What did the air filter look like when replaced? Was there anything in the smoke that could have effected the combustion chamber?

I am guessing something may be damaged but I believe your tractor is old enough to be purely mechanical on the fuel injection system so can’t really see how the fire would damage the injection system.

Did you cut open the fuel filter(s) to see if there was anything that was suspicious inside?
Thanks Russell. Yes, tractor front was in high heat with lots of thick smoke with wind. Tractor was sucking dirty air into engine intake and fuel tank cap. The outer air filter was dirty, inner air filter was clean. I will look for fuel filter, hopefully it is still in my garbage, but it was dirty. Fire was from dry, tall, wild grass so it was a normal fire i.e. no chemicals. Bucket and front tires took a beating, but remainder of tractor seems fine. Front grille is plastic, looks good, no melted spots, and no deforming. Not very much wiring in this tractor but wiring around engine and starter is Ok. No sign of melting anywhere. Bucket hydraulic hoses are fine. The thought crossed my mind that one or two injectors could have crap inside them.
 

Russell King

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Lifetime Member

Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
6,562
2,163
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Austin, Texas
Well one other thought on it is maybe it overheated? I don’t know why that would keep it from starting now or why it continued to run until parked though.

I would look in the front of the radiator at a screen and make sure it is not melted (it is plastic on my tractor). If not melted I would clean it and the exterior fins of the radiator just to be safe.
 
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LawEd

New member

Equipment
B7500HST
Jun 5, 2025
15
3
3
Alberta
Well one other thought on it is maybe it overheated? I don’t know why that would keep it from starting now or why it continued to run until parked though.

I would look in the front of the radiator at a screen and make sure it is not melted (it is plastic on my tractor). If not melted I would clean it and the exterior fins of the radiator just to be safe.
Thanks Russell... My tractor must be old style because the screen in front of the rad is ridgid metal with metal framing. There will have to be a comprehensive maintenance done on the cooling system, hydraulic oil front and back, repaint on bucket and bucket rams, etc. This tractor has always run cold. I don't think it overheated. It definitely didn't boil over.
 
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BAP

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2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
Dec 31, 2012
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New Hampshire
Follow Russell’s advice on checking the injectors. My Dad had a B7500 and at one point, 1 injector crapped out and the tractor would not start.
 
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LawEd

New member

Equipment
B7500HST
Jun 5, 2025
15
3
3
Alberta
Follow Russell’s advice on checking the injectors. My Dad had a B7500 and at one point, 1 injector crapped out and the tractor would not start.
Ordered three new OEM injectors. Could have paid to have them tested but decided tractor is 21 years old in any case, money better spent on replacement. Face the situation and be more confident in operation. Cost $300.00 CDN each or about $28.00 US (ha ha)