Kubota Engine 3 Cylinder D722 this is in my Onan Generator

Emoneyblue

New member

Equipment
Kubota D722 / Onan 8000
Aug 7, 2020
9
0
1
Chandler AZ
Hello folks,

New to the forum and want to say thank you in advance for all your help!

I had my generator in storage and left it sitting for about 8 months without starting and it was running perfect before that. It has about 2100 hrs on it and when I tried to start it gas is going through the pump but not going thru the injector pump so I was looking to replace that so as I was removing covers I found what looks like a capacitor and I don't know if this goes to my unit or just fell in there during a service. I found it in the front of the unit on the right side of pic 1. Can anyone tell me what it is and what it does or is it just something that fell in?

again thanks for any help,
E$
 

Attachments

bx tractorjoe

Active member

Equipment
kubota l2501 upgraded from a bx23s john deere 670 husquarvana huv 4421 gxp
Jun 3, 2020
258
140
43
loxahatchee flordia
I fix generators for a living and have never seen a capacitor attached to the injection pump.. may have something to do with your what looks to be electric governor above the i injection pump.

Also have never seen that kind of governor on a kubota.. ill take a guess and say your generator runs at various speeds because its a inverter generator

What model generator is that? Onan 8000 qd?
 

D2Cat

Well-known member
Lifetime Member

Equipment
L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
13,884
5,687
113
40 miles south of Kansas City
Looks like a start capacitor removed from something. Held on by a strap clamp around the center. Welcome to the forum. I'm guessing your engine uses diesel. :D
 

Emoneyblue

New member

Equipment
Kubota D722 / Onan 8000
Aug 7, 2020
9
0
1
Chandler AZ
I fix generators for a living and have never seen a capacitor attached to the injection pump.. may have something to do with your what looks to be electric governor above the i injection pump.

Also have never seen that kind of governor on a kubota.. ill take a guess and say your generator runs at various speeds because its a inverter generator

What model generator is that?

Onan 8000 diesel quiet model Ku
Looks like a start capacitor removed from something. Held on by a strap clamp around the center. Welcome to the forum. I'm guessing your engine uses diesel. :D

Yes its a diesel Onan 8000
 

Emoneyblue

New member

Equipment
Kubota D722 / Onan 8000
Aug 7, 2020
9
0
1
Chandler AZ
I fix generators for a living and have never seen a capacitor attached to the injection pump.. may have something to do with your what looks to be electric governor above the i injection pump.

Also have never seen that kind of governor on a kubota.. ill take a guess and say your generator runs at various speeds because its a inverter generator

What model generator is that? Onan 8000 qd?

D722 / Onan 8000 deisel
 

Emoneyblue

New member

Equipment
Kubota D722 / Onan 8000
Aug 7, 2020
9
0
1
Chandler AZ
Are your getting fuel to the return line? But nothing at the injectors?

Im not seeing any fuel in the return line.

When I crank it and I crack the screw on the injector pump the fuel shoots out but when I took apart the fuel line on top next to the glo plugs very little fuel if none is coming out while it cranks.
 

HermTDI

Member

Equipment
Kubota GR2120
Jan 13, 2013
35
6
8
Richomnd, Maine us
As for the fuel delivery problem..
Have you verified "positive fuel delivery" to the #1 injector ?
With the battery at a full charge... using a 17MM wrench and crack open the #1 B-nut at the injector and then crank the eng. to see if you have fuel sputtering at the B-nut. Then continue with inj. #2 & #3 .

Remember you need a minimum of 250 RPM (cranking) to achieve diesel ignition
 

Emoneyblue

New member

Equipment
Kubota D722 / Onan 8000
Aug 7, 2020
9
0
1
Chandler AZ
As for the fuel delivery problem..
Have you verified "positive fuel delivery" to the #1 injector ?
With the battery at a full charge... using a 17MM wrench and crack open the #1 B-nut at the injector and then crank the eng. to see if you have fuel sputtering at the B-nut. Then continue with inj. #2 & #3 .

Remember you need a minimum of 250 RPM (cranking) to achieve diesel ignition

Dont know which one is #1 but I pulled off the left sided one and little to no fuel while cranking. Also, did not no about the 250 rpm requirement as the battery is a bout low i put it on a boost charger Thanks will try all this next.
 

HermTDI

Member

Equipment
Kubota GR2120
Jan 13, 2013
35
6
8
Richomnd, Maine us
Dont know which one is #1 but I pulled off the left sided one and little to no fuel while cranking. Also, did not no about the 250 rpm requirement as the battery is a bout low i put it on a boost charger Thanks will try all this next.
..
Cyl #1 is the cyl. that closest to the fan.
You only need to slightly loosen the inj B-nut.
If you remove the line and crank the eng. you risk ingesting air into the pump.
Simply loosen the inj. B-nut as you crank the eng. Once you see fuel sputtering out ...then tighten the b-nut. Then continue to the #2 cyl.
 
Last edited:
  • Like
Reactions: 1 user

PoTreeBoy

Well-known member
Lifetime Member

Equipment
L35 Ford 3930
Mar 24, 2020
2,828
1,544
113
WestTn/NoMs
Is there a way to test it?
Without a manual, you'll need to do some detective work. 3 possibilities:
1. Manual shutoff - there'll be a knob and cable. No solenoid at all.
2. Normally energized - power required to run. These are usually complicated by the fact that they have 2 coils inside. A hold coil is connected to the run connection on the ignition switch, and a pull-in coil connected to the start connection. Both coils are energized to activate the solenoid, then one coil has sufficient force to hold it so one is depowered to keep from burning the solenoid out. This one has 3 connections, usually 2 wires and the case is the ground. Each wire to case will test low ohms and wire-to-wire will be the sum of the 2.
3. Normally de-energized - this one has a timer that activates the solenoid for about 10 seconds when the ignition switch is turned off. This one only has 2 connections, but I think it can use 1 wire and the case or 2 wires. You can tell by the wire or wires in the harness and by using an ohmeter.

This got wordy, but the bottom line is to figure out how the fuel shutoff on the injector pump works and make sure it's not stopping your fuel flow.
 

Emoneyblue

New member

Equipment
Kubota D722 / Onan 8000
Aug 7, 2020
9
0
1
Chandler AZ
Without a manual, you'll need to do some detective work. 3 possibilities:
1. Manual shutoff - there'll be a knob and cable. No solenoid at all.
2. Normally energized - power required to run. These are usually complicated by the fact that they have 2 coils inside. A hold coil is connected to the run connection on the ignition switch, and a pull-in coil connected to the start connection. Both coils are energized to activate the solenoid, then one coil has sufficient force to hold it so one is depowered to keep from burning the solenoid out. This one has 3 connections, usually 2 wires and the case is the ground. Each wire to case will test low ohms and wire-to-wire will be the sum of the 2.
3. Normally de-energized - this one has a timer that activates the solenoid for about 10 seconds when the ignition switch is turned off. This one only has 2 connections, but I think it can use 1 wire and the case or 2 wires. You can tell by the wire or wires in the harness and by using an ohmeter.

This got wordy, but the bottom line is to figure out how the fuel shutoff on the injector pump works and make sure it's not stopping your fuel flow.

Read this twice and each time I got more confused. but, I think I have the jist of it. Today is my birthday and wifey wont let me go out and play till Monday. Thanks :p