d722 problems

[stevedolan]

Hi first post here,though i have always found great info on this site

Here's the problem: Bobcat mt50 powered by kubota d722

Motor is hard to start, will run fine once started (idle or higher speeds) however when you put the machine to work within a couple of minutes the motor will die down to a rough idle and or stall under load. If I let it sit for a few minutes I can usually work it for a little bit longer.

I have had this machine for about 4 years and this has been an ongoing issue usually partially solved by changing fuel filters and draining the tank. I have just finished doing that and no luck this time

It seems to be a fuel supply issue but i dont know enough about diesels rule out compression or other problems

Any thoughts or suggestions would be appreciated.

steve

 

[tractorworks]

Kubota's tend to like glow plug. Even in the summer, in the south, up to 8 seconds. If you are sure the fuel filters (more than 1?) are clean it could be hydraulic filter. When was the last time it was changed/cleaned. I'm sure there are others who know more than I, but since no one had posted yet I figured I'd reply.
Doug

 

[stevedolan]

Hi thanks for the reply.

It definetly needs a glow plug to start even when its a little warm.

I will see what kind of junk is in the hydraulic filter I
havent changed it in 4 years so it is due

I saw a thread here about a clogged fuel tank outlet that caused similar problems.I might try running it out of a 5 gallon tank and see if that helps

Any other ideas?

Steve

 

[tractorworks]

Not sure about your specific machine but I've had problems with fuel pump with built in filter. Both in the tank (JD 455 garden tractor) and outside the tank (Mitsubishi 55 trackhoe).
Good luck
Doug

 

[stevedolan]

I put an electric fuel pump in and that seems to have solved the problem

 

[amhjab]

i believe the mt50 has an intank filter, when it gets clogged cause loss of power, fuel starvation. and will sometimes die under load or high rpm

 

[SSdoxie]

MT50 did not have a screen on the pickup tube, small peice of grit could be stuck in the diaphragm of the lift pump. Put an inline filter on the fuel line coming out of the tank to keep grit out of the new electric pump.

MT 52 & 55 do have screen in the tank.

 

[Bobcatman]

D722"s in mt 52/55 are known to be a problem engines because of inadequate cooling, bobcat offers an upgrade! Also in early machines there was a engine oil lube problem on steep slopes, would not lube entire engine. Check fuel filter and suction screen in tank.