Export thread

Hi Guys need some help

I have a 1995 Kubota B4200 4 wheel drive with a 2 cylinder 12 HP diesel engine with 812 hours. It has been loosing power

Put a new fuel filter and no water in the fuel. Added diesel additive and let run for a while and no change

Got any ideas

Thank John O

Does it only have one fuel filter?

cpurvis said:

Does it only have one fuel filter?

Click to expand...

Yes only the one by the manual

Did you check to see if the valves are opening and closing by looking through the oil cap in the valve cover? I did hear of a Kubota engine pushing it's cam bearing out.

I did have the bolt holding the pulley/harmonic balancer on the front of the crank back out (although this was on a Yanmar 2 cylinder diesel).

Check the air filter? Did you bleed the fuel line after replacing the fuel filter?

Other than the above, there's not a whole lot you can check on a diesel. It's possible to have a bad injector pump or injector or low compression,,,hard to tell without taking it to a Kubota dealer.

Regards

Jeff

johno778@cox.net said:

Yes only the one by the manual

Click to expand...

Can you describe the problem in more detail?

About the only things that will cause a diesel to lose power is lack of fuel, something wrong with the injection $ystem, damage to valves or overheating. Most of the time, it is simply lack of fuel. That's not to say it can't be an internal engine problem but most of the time, it's a lack of fuel.

Did you bleed the fuel system after installing the new filter?

Are you the original owner or is there a chance someone else took it upon himself to install an inline pre-filter that you haven't noticed?

When it loses power, if you shut the engine off and restart, does the engine then run any better?

Does it have full power when you first start it (from a cold condition)?

What does the exhaust look like? Black smoke, no smoke, other? Smooth or irregular? If black, check your air filter.

Is the fuel gravity fed or does it have a fuel pump to feed the injection pump?

Any difference in the sound of the engine when it loses power?

I am not a diesel tech but I've owned my fair share of diesels, both tractors and trucks, over the years. Loss of power, in my case, has always been a fuel filter that needed replaced. If your engine was running OK and suddenly developed this problem, that would be where I would look first.

I just Googled power loss on a small diesel and the one thing to add which hasn't already been mentioned is muffler plugged?

Regards

Jeff

Good point about the muffler.

jp1961, I didn't see your post above mine before I posted or mine would have been a lot shorter.

Check your air filter. Many times they will stop up and cause air flow problems.

Can you describe the problem in more detail?

About the only things that will cause a diesel to lose power is lack of fuel, something wrong with the injection $ystem, damage to valves or overheating. Most of the time, it is simply lack of fuel. That's not to say it can't be an internal engine problem but most of the time, it's a lack of fuel.

Did you bleed the fuel system after installing the new filter? No I did not I filled the bowl. The problem was before the filter that is one of the reasons I changed the filter

Are you the original owner or is there a chance someone else took it upon himself to install an inline pre-filter that you haven't noticed? I am not the original owner and I looked around and did not see anything unusual.

When it loses power, if you shut the engine off and restart, does the engine then run any better?. The engine runs the same from start up to shut down

Does it have full power when you first start it (from a cold condition)? No the same all the time

What does the exhaust look like? Black smoke, no smoke, other? Smooth or irregular? If black, check your air filter. First start it is a little black and then just about none

Is the fuel gravity fed or does it have a fuel pump to feed the injection pump? I believe it is a fuel pump

Any difference in the sound of the engine when it loses power? The lost power is from is from start up

I am not a diesel tech but I've owned my fair share of diesels, both tractors and trucks, over the years. Loss of power, in my case, has always been a fuel filter that needed replaced. If your engine was running OK and suddenly developed this problem, that would be where I would look first. Correct that is why I changed the filter but I ran it yesterday and it seemed to run better after the additive may have cleaned something out not real good but it definetly was better.

I put a diesel additive in and ran it for a while with no change, yesterday I went out to get a load of fire wood and it seemed to run a little better where I had some power maybe not full but more. So maybe the injectors are dirty and this additive will clean them out I HOPE! the additive is Power Service, Diesel Kleen injector cleaner and performance improved. I HOPE THIS WORKS

thanks for your help and I will add to this in a few days THANK YOU did not know how to change color to the text or it would have looked better



Reply With Quote Reply With Quote Multi-Quote This Message .

--------------------------------------------------------------------------------



Yesterday, 02:49 PM
#6


jp1961











jp1961 is online now

Can you explain your last comment please?

I'm pretty sure you have air in the injection system.

Additives are not the answer. Dirty injectors would have other symptoms.

Get a new fuel filter and install it correctly, which means bleed the air out of the system which may have gotten in while changing the filter. Nothing stops a diesel engine from running quicker than getting air in the injection system. I'm surprised that your engine runs at all if you just put a fuel filter on it without bleeding the system.

I can't tell you how to bleed your system. If you have a Kubota owners manual, it should tell you. If you don't have a manual, maybe this site has a pdf you can use. https://hostpdf.com/kubota-b4200-tractor-service-manual/

Good luck.

Edit to add: You probably ought to verify that the lift pump (the pump that sends fuel to the injection pump; you said you thought it had one) is working.

Guys

After I added the fuel additive and let it run and sit for a while it is running good again

I pulled the air filter and it was clean all the way to the engine, the fuel filter was clean and no water in the fuel bowl

Had to be dirty injectors or air in the system that worked its way out

Thank you for all the help

Merry Christmas and a happy new year

John