Mowing Kubuto ZD28 Loss of Power

[freycorm]

I own a 2004 Kubota ZD 28 (diesel with 72" deck) zero turn mower. Mower runs fine at first, but as it heats up, loss of power is experienced. When it happens, it smells like it is running rich (diesel smell). We have changed filters, cleaned (and changed) fuel lines, dropped and cleaned fuel tank, etc. We have also checked all valves and compression and all are fine. We have also watched the fuel filters when we experience the loss of power, and the filters have normal fuel levels running through them. Mechanics that have done this work for us are at a loss.....can't figure out what else it could be. Any suggestions?

 

[stevewarner1957]

No restriction on the intake side? Air filter(s) etc

 

[freycorm]

we changed the air filter, and no restrictions observed on the intake

 

[stevewarner1957]

Ok. Just a thought. That will give low power/rich condition

 

[freycorm]

Ok - thanks for the response. It only has the loss of power after mowing for a period of time.....basically after engine is hot. I can mow for 45 minutes or so and it runs perfect, then all of the sudden it starts running bad and loss of power. Does it every time.

 

[stevewarner1957]

Well that indicates something else that is heat related. Something opening up from expansion.

 

[johnrdunn1953]

How about the muffler? Anything loose in it? Also could be a sticking injector when it get hot. I run some injector cleaner in my ZD21 about every 3rd tank( run red dye diesel)

 

[dodge man]

Lift pump? Just a guess on my part.

 

[Gem99ultra]

Sounds a bit like vapor locking... Does your fuel line lay close to the engine block, or near the exhaust?
Another thought, maybe some trash is floating around in your fuel tank and finally gets sucked down close to the outlet, causing somewhat of a fuel starvation or restriction.

 

[diesel85]

How many hours on the machine?