bobcat engine problems

[thomasedwin]

I have a 1982 or 1983 bobcat 643 skidsteer / loader with a kubota deisel engin, It takes a bit of cranking to get it started but once started it runs good for about 10 minuts then it loses hydrolic power and the engine bogs down and stops and won't restart. After about 10 minuts or so it will start back up and run for about 10 minuts again and then lose power bog down and quit again. Anyone had this probem or know how to fix it????:Banghead

 

[Dig_Texas]

First place I would check would be all the fuel filters and screens.

 

[willie59]

First of all, glow plugs have to work well on those model engines, and if the engine has some hours on it, even with glow plugs, they don't fire off quickly.

When engine stalls and dies, pop the rear door open and check the rubber fuel primer bulb. If it's collapsed flat, you've got a fuel restriction.

You have changed the fuel filter, no?

I've never worked on a 643, but on a 743 there's a fuel shut off valve on the right side of the machine. If yours has this valve, have you check that it's fully opened?

If you still have the problem, likely something clogging the pick up strainer inside the fuel tank.

 

[thomasedwin]

The people that had it didn't matinance it very well, I thought about draining the tank and flushing out the fuel everywhere I can, replacing the filter/screens then filling it back up, bleeding out the air and see what happens. I had thought it might have been some kind of intermitant injector pump problem like maybe when it got warmed up good it would quit working or maybe the fuel sylenoid was cuting off the fuel, Im no to familure with this animal, Im not sure it has a fuel sylenoid. Thanks, I will send back after I do filters and screens.

 

[crewchief888]

if all the glow plugs aint working, the 643/743 are very hard to start, even on a warm day.

as willie mentioned, sounds like you have a fuel delivery problem,

there is a long hose with a screen/check valave in the tank, screen could be plugged up, the fuel shutoff valve could be partially shut off, or could be clogged with debris, or the filter could be plugged

:drinkup

 

[willie59]

Did the 643 have that two piece filter/water bowl like the 743 did?

 

[crewchief888]

Did the 643 have that two piece filter/water bowl like the 743 did?

yep it does.

3975315B <--bobcat PN hasnt changed since '84

it's probably a bad thing that i remember it,
when i cant remember my phone #

:drinkup

 

[willie59]

yep it does.

3975315B <--bobcat PN hasnt changed since '84

it's probably a bad thing that i remember it,
when i cant remember my phone #

Ahh, the curse you get for working on those critters.

I hated those stupid filters. They're not really that bad, just not easy to work with compared to a spin on filter. And on a 743, it was behind the coolant recovery jug. I learned early on to approach that filter change starting with a clean container, yank that coolant recovery jug out of its mount, and pour the coolant into the clean container, then you can somewhat access the fuel filter and work on it.

 

[Dig_Texas]

Had a backhoe that would plug filters on a regular basis due to previous owner not keeping the tank full. Finally had to pull the tank to clean all the rust out and make sure I filled it up after using it. Don't know if your unit has a screen on the inlet of the pickup but if the filters are plugged I'd check that also.

 

[thomasedwin]

Did the 643 have that two piece filter/water bowl like the 743 did?

No, this one has all steel and ruber lines and a filter that looks just like a scrue on oil filter and I glanced over the manual and there are a fue in line filters:bash

 

[thomasedwin]

This bobcat has about 20 hours on it in the last year and it was used in a flower green house so Im going to pull it all apart, clean it out, all new filters nd screens and I think that might fix it.