Kubota B7800...

[Nedfan]

...cranks and idles fine. Press on the accelerator and it cuts out and wants to die, or cuts out and catches again in froward or reverse. Not good for the PTO I suspect. Could this be the fuel filter or the switch on the pedal? Thanks for any help.

 

[Rocky Hoffler]

Possible seat switch is tripped lift seat and make sure lever is held down by bracket on seat

 

[Nedfan]

Thanks. While sitting there idling, I stood up from the seat to see if it would die. It did nothing. Maybe the previous owner bypassed the switch.

 

[bumperm]

Fuel filter is one of the first things to check, though in my experience a clogged fuel filter usually "comes on" slowly with some warnings on a regularly used tractor . . . loosing power at higher throttle settings, and when the engine load is increased as when climbing a hill etc.

bumper

 

[Rocky Hoffler]

Thanks. While sitting there idling, I stood up from the seat to see if it would die. It did nothing. Maybe the previous owner bypassed the switch.

It will run as long as you don't have pto engaged. check switch to make sure its not tripped. I had a l3700 that if you hauled it on trailer the seat would bounce and switch would flip over and as soon as you moved hst pedal would shut engine down.

 

[BeezFun]

There are two switches on the seat of the B7800. One senses if you're in the seat. The other senses if the seat is folded forward, which allows you to get out of the seat and be off the tractor while the PTO is engaged, like if you want to operate a log splitter or something. So I agree with Rocky that it's probably the seat switch, just make sure you know which switch is which, then bypass the seat switch and see if it fixes the problem. My seat switch failed in the other mode, so I could get off the tractor and push on the HST pedal from the ground and the tractor would take off on it's own.

 

[teg]

Parking Brakes on? (just asking...)

 

[Nedfan]

Thanks for the replies. I am new to these tractors and appreciate the help. Changed fuel filter and it did the same thing. I was worried because it did it several tries but I throttled up and took off and it did not bog. I cut for about an hour and put it up. I will check the switches periodically.

Now, where is my fuse panel? Shorted a broke headlight and it won't crank. I can't buy a break.

 

[Nedfan]

Found the fuse box on the firewall. Too easy. Thanks for all y'all's help.

 

[Nedfan]

Checked the switch with the black button and it engages the seat. The other switch has no button so I don't know what it does. I can cut with the bush hog and it will run fine for a while, then it might just shut down. But as soon as I let off the forward pedal, it will catch and run again. It seems to do it more when I slow down to turn a corner then press to go forward again. It also does it backing up. I'm probably going to have it tuned up. I already changed the fuel filter, air filter, put fuel additives in the tank in case of water in my fuel.

Could I have an air lock and need to bleed the injectors? I'm going to try that tomorrow.

 

[David Devuono]

With the seat switch it will run as long as the fwd rev pedal is not activated. As soon as you try to move the tractor it will shut down. You might need to remove the wires from the plug, short them together and see it if works better. Just don't run overyourself.

 

[bumperm]

With the seat switch it will run as long as the fwd rev pedal is not activated. As soon as you try to move the tractor it will shut down. You might need to remove the wires from the plug, short them together and see it if works better. Just don't run overyourself.

On my tractor (B3350) it was relatively simple:

Remove plug from seat "pigtail".

Strip the insulation from both ends of a short length of solid conductor wire (one could use stranded wire if you tin the ends with solder).

Bend wire into a "U" shape.

Insert each end of "U" into the wire harness plug removed from seat.

Be careful not to run over yourself!

bumper

 

[JOHNTHOMAS]

The B7800s had a problem with not starting. It was/is the foot pedal has to be centered or it won't start. If this can keep it from starting then it may possibly affect the running by creating a intermittent off/on action. Don't know but check switch at foot pedal.

 

[sixdogs]

There are two switches on the seat of the B7800. One senses if you're in the seat. The other senses if the seat is folded forward, which allows you to get out of the seat and be off the tractor while the PTO is engaged, like if you want to operate a log splitter or something....

Wow, I have a B7800 and had no idea the PTO would run with the seat folded forward. Don't know how I missed it. Duh on my part.

The B7800s had a problem with not starting. It was/is the foot pedal has to be centered or it won't start. If this can keep it from starting then it may possibly affect the running by creating a intermittent off/on action. Don't know but check switch at foot pedal.

I'm with JT on this. Seems more likely a switch issue of some type. Problems with these little tractors are more likely switch-type related things as opposed to mechanical issues.

 

[herringchoker]

My B7800 was cutting out like that and then catching again if I shifted my weight in the seat. I realized that I was sitting a little sideways on the seat to keep an eye behind. If it starts to cut out, I shift my weight and it goes back to normal. Now that I've trained myself to correct my posture, it hasn't happened again. I'm no lightweight (230 lbs.) and I suspect that over the last 10 years the seat or its mount has worn or twisted.

 

[bumperm]

I never did master the "Messerschmidt twitch" - - my head just doesn't go around far enough to look aft without pivoting the old butt. Then the tractor engine quits, it also quits going over bumps as I get launched skyward, guess I'm a light weight. Safety be d&*^ned, I'm not gonna put up with that!

bumper

 

[number two]

Let's not forget to grease the hydro pedal on occasion to ensure it returns to the center position easily!

 

[sixdogs]

Let's not forget to grease the hydro pedal on occasion to ensure it returns to the center position easily!

For some reason I have never lubed my pedal. It just never occurred to me.
Do you use grease or a shot of oil? Seems grease could gum things up?

 

[DennisArrow]

That is one of the few things, besides the loader, that has a zerk............take a good look......easy to miss........God bless......Dennis

 

[bumperm]

That is one of the few things, besides the loader, that has a zerk............take a good look......easy to miss........God bless......Dennis

And in the off chance it doesn't have a zerk, then use a suitable spray lube like Synco SuperLube or Tri-Flow. This sort of lube has a thin carrier that allows the spray to penetrate, then the carrier evaporates leaving a thicker lubricant in place - - useful for all sorts of hinges, pivot points, Heim bearings, ball ends, etc.

Note that I did not recommend WD40 :c)

bumper