Kubota D722 Loss of Power

billycalexander · Aug 16, 2006

I have a grasshopper ZTR with a 21 hp kubota deisel industrial engine model D722. I'm having a problem with the motor losing power for usually 2-3 seconds and then building back up. Sometimes it loses power for 5-10 seconds and then builds back up and then sometimes it loses power and in ~10 seconds dies. It's been doing this essentially since I bought it used about 5 months ago but seems to be getting worse. These episodes occur every 10 to 15 minutes but are more frequent when the mower is hot. Otherwise the mower mowes/runs fine. The filter is a paper cartridge type and it was in good shape but I cleaned it anyway. This sounds like an intermittent loss of fuel. There is a fuel cut of solenoid that could be going bad or else not getting it's signal to stay actuated to allow the fuel to continue to flow or maybe there is a pump problem. Does anyone have any thoughts? I will post this on the mower forum also.

Fordlords · Aug 17, 2006

Fuel filter most likely needs replacing.

-Fordlords-

a109836 · Apr 11, 2015

Did you get your engine working, cause I'm having same problem. Already chg'd filters - - was wondering about fuel pump

Harrisburg grasshopper · Apr 28, 2025

I have similar problem and curious what you all discovered. I replaced both fuel filters (pre and main). Runs great for 45 min, the bogs down. Could it be pulling a vacuum in the gas’s tank?