Kubota zd21 losing power

zboyter · Apr 25, 2013

Hey. I have a Kubota zd21 with 700 hrs. The problem that I am having is when I try to go up a hill the motor will bog down. I then have to stop for about 10-15 seconds and the mower will regain power. It runs like a new one unless I try to go up a hill. I am the original owner and haven't had any other problems. I did replace the fuel filter but that didn't fix my problem.

Thanks for your time

Patches · Apr 25, 2013

Have you changed your air filters? Diesels need a LOT of air

Bigkrank · Apr 25, 2013

Had the same thing on a ZD28, replaced filters and electric pump. Didn't help. Found it was some dirt partially plugging the line from the tank to the first filter. Blew it out backwards and been fine ever since.

landmarr · Apr 28, 2013

I have the same mower and had the same problem... changed all the filters, checked wires, fuzes... much frustration no answers

It ended up being the tube that brings fuel up from the tank... pull tank off... pull tube out... stick hanger down tube and presto magic... I had a new mower... (warning... you can try compressed air which will cause you to think you solved it but it will probably require a hanger.

hope it works

DT86 · Apr 28, 2013

Bigkrank said:
Found it was some dirt partially plugging the line from the tank to the first filter. Blew it out backwards and been fine ever since.

I am willing to bet this is your problem also. If you do have crud in the bottom of the tank there is a second step to the compressed air I would suggest. After you blow the lines clean use a shop vac in the tank to remove most of the crud. A short piece of old water hose (or any other hose for that matter), with some duct tape to connect it to the shop vac, will help you get in the hard to reach places inside the tank.

Dozernut · Apr 29, 2013

I have a ZD21, they have two fuel filters. One is below the tank and the other is after the in-line fuel pump. The one below the tank is behind the battery, hard to get to and replace . If not the filter then Bigkrank probably nailed it.