ZD326 Bogging Down

[Luke.Boyer]

I have a ZD326 that I purchased used, only 200 hours. It now has 450 Hrs. and it is constantly bogging down. It has done this since I purchased the mower. Typically it runs fine for 20 minutes or so, and then it starts loosing power like crazy. When mowing I am constantly disengagning the blades to let it regain power. It also bogs down when not engaged.

I have replace the fuel filters and also replaced the inner and outer air filters. It bogs down on both the left and right fuel tanks.

I am not much of a mechanic so I'm a little clueless. It seemed like a fuel problem to me but I don't exactly know where to start with the exception of the filters. I thought it may be an air intake issue but I've changed the filters and I keep the screens clean.

Any help or ideas would be greatly appreciated.

Luke.Boyer

 

[Saxman]

That’s definitely not normal Luke. I have a 326 and it’s hard to make it bog down. You have done the obvious things. Does it smoke black when it bogs? I suspect something with the injection pump is amiss. Check the fuel shut off lever. Make sure it is opening up all the way. The solenoid pulls it closed to kill the engine. Make sure it’s full stroke the other way. That will limit fuel as well.


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[hope to float]

Not sure if this applies to your machine but; Take the fuel line off the first filter on the tank side and give it a quick blast of air up the pipe into the tank. If that solves it, you have an algae build-up. Now two things may have happened: 1. You have cleaned crud off the in-tank filter or, 2. You have blown that filter off the tank outlet. It is not a critical part. The inline filters are going to get the crap anyway. But a fuel additive will keep it to a minimum.
Hope this helps

 

[Luke.Boyer]

No it does not smoke. So, I am showing my complete ignorance here but where is the fuel shut off lever?

 

[Luke.Boyer]

Thank you very much Saxman and Hope_to_Float!

Luke

 

[Saxman]

Have someone turn the key in and off. You will hear a click. Look on the right side of the engine and will see a lever moving back and forth. That’s it. As stated earlier it could be Algae but I presume you run enough fuel on a regular basis it shouldn’t be. It’s still a good idea to blow the fuel lines from the first filter into the tanks. Take the fuel caps off before you do. Could be lady bugs blocking the line.


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[D2Cat]

"Could be lady bugs blocking the line."

Or a piece of foil from an additive lid, or a leaf, or .....just about anything.

 

[Saxman]

The service manager at my Kubota dealer told me last year they had a run of farmers having issues. The lady bugs would get in the bulk tank nozzles in the farmer's truck and when they filled their tractors in the field they got in the tractor tanks.


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[whitetiger]

I have a ZD326 that I purchased used, only 200 hours. It now has 450 Hrs. and it is constantly bogging down. It has done this since I purchased the mower. Typically it runs fine for 20 minutes or so, and then it starts loosing power like crazy. When mowing I am constantly disengagning the blades to let it regain power. It also bogs down when not engaged.

I have replace the fuel filters and also replaced the inner and outer air filters. It bogs down on both the left and right fuel tanks.

I am not much of a mechanic so I'm a little clueless. It seemed like a fuel problem to me but I don't exactly know where to start with the exception of the filters. I thought it may be an air intake issue but I've changed the filters and I keep the screens clean.

Any help or ideas would be greatly appreciated.

Luke.Boyer

Remove the fuel hose from the injection pump, it's behind the throttle lever. Hang the hose over a catch can and turn the key switch to RUN position. You should get a full stream of fuel pulsing out of the hose. Switch tanks and check both.

You will most likely only get a slight trickle of fuel which means the draw tubes in the tanks are plugged with debris. The tank will need to be removed, cleaned and the draw tubes blew out. While it is apart, remove the supply hose to the first filter and blow backward thru the hoses and switch valve. Do with valve in Left and Right position to make sure there is nothing stuck in it.

I run into this probably 20-25 times a year. I have one waiting to do tomorrow or Thursday and a ZD25 probably Monday.

 

[whitetiger]

That’s definitely not normal Luke. I have a 326 and it’s hard to make it bog down. You have done the obvious things. Does it smoke black when it bogs? I suspect something with the injection pump is amiss. Check the fuel shut off lever. Make sure it is opening up all the way. The solenoid pulls it closed to kill the engine. Make sure it’s full stroke the other way. That will limit fuel as well.


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300 series ZD's have a solenoid mounted on the rear of the injection pump and the rod that pushes the linkage is inside the pump. You can not see it.

 

[Saxman]

My apologies, many Kubota engines have the external lever. I should have looked at mine.


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