Kubota 125s begins to lose power after warm up.

[slomo]

I would suggest replacing all of the fuel lines. There is a high probability that they are deteriorating on the inside.

So true. We can't see internal fuel line deterioration which impedes fuel flow. Replace hoses from tank to carb completely. Good call MParr.

 

[MParr]

Power loss on hills and sharp turns is another indicator of fuel delivery problems.
Trash is moving around in the fuel tank. The fuel needs to come out of the tank or tanks and the tank or tanks need to be cleaned.
DO NOT use a powered pump to remove the fuel.
The steps that I have described here and above will cost very little.

 

[doc craker]

I will double check fuel lines and filter.

Yes I cleaned the fins after reading your signature.
I'm willing to double or triple check anything.
I have 2.5 acres of yard to mow.

thanks
Doc

 

[slomo]

I will double check fuel lines and filter.

Just replace them. Only a few bucks. Guessing they are original to the now 9 year old mower.

 

[slomo]

Pull the fuel hose off AT the carb inlet. See what you have. Nothing, trickle or a flood.

 

[doc craker]

ok. appreciate all the help.
I have a few questions.

So, the plan at this point is to replace all the fuel lines and filter. Filter is pretty new and still clear, but I have another one.

I did notice this morning that the fuel filter was empty before start up. Is this normal? It's not the best thing one my old jeep. Just curious.

If I do spot trash in the tank, what's next? How to clean, is it a chore to remove? It looks like it?

What is the electronic looking device attached to the bottom of the carb? What's it do? (see, not a mechanic lol)

Should I replace the fuel pump even though it is working? It works when the engine is cool for sure.

Just getting an idea before I start the work.

Going to borrow a mower to mow my yards.

Local shop charges 125.00 an hour labor. Since it takes almost an hour of running the PTO before it malfunctions, I will be paying some shop guy a 125.00 just to drive it around.
NOT wanting to do that.
Thanks
Doc

 

[slomo]

So, the plan at this point is to replace all the fuel lines and filter. Filter is pretty new and still clear, but I have another one.

Cut or remove your old fuel line. Probably hard as a carp. Take it to an auto parts store for replacement. Get a couple extra feet for fuel filters and shut off valve installs. Install ALL new fuel line and filter, tank to carb inlet.

I did notice this morning that the fuel filter was empty before start up. Is this normal?

No. Sounds like lack of fuel delivery. Reason I told you to pull the fuel line off AT the carb inlet and test. Possible dead pump if your engine has one or clogged hose, tank or filter.

If I do spot trash in the tank, what's next? How to clean, is it a chore to remove? It looks like it?

If you see trash it HAS to come out, end of message. Could take time. It's a 2 second job on a Snapper. Could be a 2 day job on a Kubota I don't know. Hopefully it's simple you can follow the lines and bolts. Maybe one of the others here has worked on a machine like yours??

What is the electronic looking device attached to the bottom of the carb? What's it do? (see, not a mechanic lol)

That is an anti backfire solenoid. Prevents excess fuel in the cylinder and or muffler from making a loud near gun fire sound which my neighbors LOVE. Stops fuel flow to the carb main jet when you turn the key off. Key on, sends battery voltage to this solenoid, retracts the solenoid plunger, passing fuel to the carb main jet. Key off, kills battery voltage to solenoid, plunger extends, stopping fuel flow to the main jet.

Should I replace the fuel pump even though it is working? It works when the engine is cool for sure.

You need to percolate on that one. Read what you typed again. AND the same reason I asked to pull the hose off AT the carb inlet for testing. THIS will verify if your pump is good or not. You need to crank the engine most likely for your pump to work. Could be an electric pump, not sure. If it is a pulse pump, need to crank the engine over.

 

[MParr]

There is an arrow on the fuel filter. The arrow indicates the direction of flow. The arrow must be pointed towards the carburetor.

 

[doc craker]

all fuel lines replaced. New filter. Yes, I got the arrow facing the right way.

There was no fuel at the carburetor line. I think it was old swollen lines.
After cranking for a minute fuel is in the filter again and all cylinders are firing.
I got done too late to do a full hour test. Perhaps after dinner.
IF not I will do it in the cool of the morning and hope that helps.
Cleaned carburetor and throttle linkage with spray.
Cleaned air filter and housing.
Made sure cooling fins were still clear.
I think that was it.

I will post results this evening or in the morning.

thanks
Doc

Oh yeah. The fuel tank is clean and clear. I used an endoscopic camera to inspect the bottom of the tank and surrounding area.

 

[slomo]

all fuel lines replaced. New filter. Yes, I got the arrow facing the right way.

There was no fuel at the carburetor line. I think it was old swollen lines.
After cranking for a minute fuel is in the filter again and all cylinders are firing.
I got done too late to do a full hour test. Perhaps after dinner.
IF not I will do it in the cool of the morning and hope that helps.
Cleaned carburetor and throttle linkage with spray.
Cleaned air filter and housing.
Made sure cooling fins were still clear.
I think that was it.

I will post results this evening or in the morning.

thanks
Doc

Oh yeah. The fuel tank is clean and clear. I used an endoscopic camera to inspect the bottom of the tank and surrounding area.

WHEW HEW!!!!! I knew you could do it. Glad to hear she is a runner.

Some cool stuff what you learned about deteriorating fuel lines from the INSIDE. That and she likes a steady diet of unleaded.

Tiger Small Engine called it with a clog in the fuel line. Nice job as usual Tiger!! Page 1 reply #7.