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Small Kubota engine won't start

Stevenbrla

Well-Known Member
Joined
Aug 28, 2010
Messages
175
Location
Louisiana
I've got a small Kubota diesel engine on my Donkey forklift.

It was starting just fine (to my recollection). Then it wouldn't start one day... I opened the fuel bleed and pretty sure I got the air out of the line, still wouldn't start... I ran the battery down trying to start it... this was about 3 months ago...

I haven't needed it, so I haven't messed with it, but I'd like to get it going now...

Suggestions? New plug(s)? Ether? Gasoline?

Thanks!!
 

willie59

Administrator
Joined
Dec 21, 2008
Messages
13,361
Location
Knoxville TN
Occupation
Service Manager
Does it have glow plugs? Depending on model of engine and degree of engine wear, if it's an older pre-combustion chamber Kubota it will hardly hit a lick without glow plugs.
 

Stevenbrla

Well-Known Member
Joined
Aug 28, 2010
Messages
175
Location
Louisiana
I would assume it has glow plugs. It's circa 1997. You can turn the key to the left to warm the glow plugs (I assume.)

So I need to try replacing the plugs?
 

willie59

Administrator
Joined
Dec 21, 2008
Messages
13,361
Location
Knoxville TN
Occupation
Service Manager
I would first verify the glow plugs are getting 12V power, then verify the are getting hot.

Aside from that, hard for us to say why it won't run on your Donkey forklift, I've never even seen one. A diesel engine is typically simple; fuel, air, compression and they run, a lack of any of these three they won't, old Kubotas require the fourth thing, glow plugs. If you've verified injection pump is getting fuel, have you verified that fuel is being delivered to the injectors?

You can test glow plugs by ohms value, don't remember what the value is though, sorry.
 

Stevenbrla

Well-Known Member
Joined
Aug 28, 2010
Messages
175
Location
Louisiana
Thanks Willie... I'll play around with it... as you said, can't be that much to it.

And for kicks, I'll add a few Donkey pics. For my application, its the best tool I know of. It only weighs 3200 lbs, supposedly lifts 4000 lbs... so it works great hanging onto my medium duty flatbed truck. I own three of them, purchased all used. They're manufactured in Denver, CO and have great customer service.


wp0b29a26c_0f.jpg


wp5f05e00d_0f.jpg
 

wildhorse trnr

Well-Known Member
Joined
Feb 13, 2010
Messages
78
Location
Texas
Occupation
Field Technician
If the glow plugs are OK, did you actually crack the lines @the injectors to verify fuel and air out? If the units not a tier 3/4 you can still check them that way. I had one on an old pump that I rarely use at my place and it failed to start after a long winter, turned out it was the lift pump but that was not on a stowable lift. Do you know what model Kubota it is? When I used to work @ the bobcat dealer we had to r/r the delivery valves on alot of units as they got older (but that was mainly due to bad fuel).
 

dist3

Well-Known Member
Joined
Mar 23, 2008
Messages
110
Location
Connecticut
Occupation
Equipment Manager Enviromental and Site Contractor
Don't some of the Kubota engines have a transfer pump before injection pump? If I remember correct when they fail they tend to be hard starting.
 

Stevenbrla

Well-Known Member
Joined
Aug 28, 2010
Messages
175
Location
Louisiana
I'll get the Kubota model number when I get back to my shop.

Unfortunately, I really don't even understand the general concept, much less one kind of pump from another.

Only thing I know, is that when I change a fuel filter (or once let it run out of fuel), it has a pump on the side (that I can barely see), and it has a screw that I can partially unscrew, and it has a little manual thumb pump... which I pump until fuel comes out of the screw... screw in, and usually starts.

This particular motor had been starting, and one day it didn't. I'm thinking I had recently changed a filter, so I bled the line (as I just described), but it wouldn't start.
 

5030tinkerer

Active Member
Joined
May 11, 2012
Messages
44
Location
Iowa
When you run a diesel out of fuel, it sometimes takes seemingly forever to get them to start. Don't overheat the starter, don't draw down the batteries, and be sure that there is fuel being delivered.
 
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