L3902 winter operating problem

Buckthorn guy

New member

Equipment
L3902
Jan 25, 2024
3
0
1
Wisconsin
I have a 2 year old L3902 that starts fine in cold weather (Wisconsin winter) as long as the block heater is pugged in but, even after allowing it to warm up after starting it in cold weather, it will stall out once I engage the transmission to move forward or backward. Has anyone else experienced this and what do you do to overcome it?
 

Fordtech86

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L3200
Aug 7, 2018
4,976
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Pineville,LA

I wouldn’t go drilling holes in the seat yet, but being a new model and it sounds like they changed the seat and seat switch from the previous models, there maybe something common happening.
 

ajschnitzelbank

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L4701, BH92, Frost Bite grapple, Logosol M8 mill, Stihl MS661
Aug 24, 2021
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Rensselaer County NY
The seat safety switch freezes on my L4701. I found that holding it with an un-gloved hand warms it up so the little black plastic piece moves up and down freely, then it works. It’s a pain. I’m tempted to zip tie it down.
 
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Steve’s3902

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Equipment
Kubota L3902
Jan 7, 2024
2
4
3
71
Tennessee
The seat safety switch freezes on my L4701. I found that holding it with an un-gloved hand warms it up so the little black plastic piece moves up and down freely, then it works. It’s a pain. I’m tempted to zip tie it down.
I just bought my 3902 a couple of weeks and and have just now started using it. My seat switch was frozen up last Monday so I decided the good Lord wanted me to do nothing. But yesterday I did manage to spread about 100 feet of gravel and was pleased with how it turned out. And my wife was happy so all is good. But today I spent a good amount of time reading up on what not to do while operating a tractor. The last tractor I owned was a 1949 Ford 8N, so this Kubota is a new experience for me.
 
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D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
I just bought my 3902 a couple of weeks and and have just now started using it. My seat switch was frozen up last Monday so I decided the good Lord wanted me to do nothing. But yesterday I did manage to spread about 100 feet of gravel and was pleased with how it turned out. And my wife was happy so all is good. But today I spent a good amount of time reading up on what not to do while operating a tractor. The last tractor I owned was a 1949 Ford 8N, so this Kubota is a new experience for me.
You can say that again!!! Congratulations.
 

TheOldHokie

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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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Myersville, MD
windyridgefarm.us

I wouldn’t go drilling holes in the seat yet, but being a new model and it sounds like they changed the seat and seat switch from the previous models, there maybe something common happening.
Yep - L3301 and L3901 used a different switch that was not embedded in the seat.

Dan
 
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specialtool

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Equipment
B7100
Jan 6, 2024
8
14
3
Connecticut
I have a 2 year old L3902 that starts fine in cold weather (Wisconsin winter) as long as the block heater is pugged in but, even after allowing it to warm up after starting it in cold weather, it will stall out once I engage the transmission to move forward or backward. Has anyone else experienced this and what do you do to overcome it?
That is an engine load based problem.
Im sure you have put anti- gel in your fuel and you have changed your fuel filters?
Also - keep in mind that fuel purchased in spring or summer will not have anti gel in it, distributors start doing that in fall, depending on station delivery zones.
 

TheOldHokie

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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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Myersville, MD
windyridgefarm.us
That is an engine load based problem.
Im sure you have put anti- gel in your fuel and you have changed your fuel filters?
Also - keep in mind that fuel purchased in spring or summer will not have anti gel in it, distributors start doing that in fall, depending on station delivery zones.
No - its a well documented OPC safety cutout problem.

Dan
 

Foxrunfarms

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Equipment
Kubota LX2610, 1951 Farmall M, 1967 John Deere 110 Rf, 2010 Arctic Cat 700
Apr 25, 2023
366
522
93
WI
I have a 2 year old L3902 that starts fine in cold weather (Wisconsin winter) as long as the block heater is pugged in but, even after allowing it to warm up after starting it in cold weather, it will stall out once I engage the transmission to move forward or backward. Has anyone else experienced this and what do you do to overcome it?
As mentioned above any antigel in it? I too live in WI. I usually let my lx2610 idle for 10 or 15 minutes and even then kind of slow responsive.
 

Buckthorn guy

New member

Equipment
L3902
Jan 25, 2024
3
0
1
Wisconsin
That is an engine load based problem.
Im sure you have put anti- gel in your fuel and you have changed your fuel filters?
Also - keep in mind that fuel purchased in spring or summer will not have anti gel in it, distributors start doing that in fall, depending on station delivery zones.
Thanks for the reply. I haven't put anti-gel in the fuel as I didn't know that was needed. My bad. I didn't do it last winter and I didn't have any problems. Maybe beginners luck@
 

TheOldHokie

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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,931
4,672
113
Myersville, MD
windyridgefarm.us
Dumb question - what's OPC stand for? What's the solution to this OPC safety cutout problem? Thanks.
Questions are never dumb.

OPC = Operator Presence Control

In this case its a pressure switch embedded in the seat that signals the presence or absence of the operator in the seat. For safety reasons the computerized engine controls will shut the engine off if the HST pedal is engaged when the operator is not in the seat.

Problem:

In cold weather the switch can freeze and fail to operate causing the computer to think the operator is not seated when in fact he/she is. When that happens every time you touch the HST pedal the computer kills the engine.

Fix:

Warm the seat enough to thaw the switch. Or for some jumper the switch to completely disable the OPC safety interlock.


Maybe Kubota needs to offer a heated seat option on the L02s like on my BMWs 🤔

Dan
 
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jimh406

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Kubota L2501 with R4 tires
Jan 29, 2021
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Western MT
I didn't know any L3902s were 2 years old. Have you done the maintenance?

Other than that as strange as it sounds, I'd probably look at spraying your seat switch down with electric contact spray or similar to try to prevent freezing assuming it is in the humidity/rain.