Hope someone can help

[gregjo1948]

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.

Spring tension on governor is slightly off.

 

[Jughead]

Gumout

 

[StarTech]

Come on guys read the whole dang thread. JD said it was water in the fuel on in post 30. Most likely in the carburetor fuel bowl. Doesn't take all that much either nor does it takes that much in the fuel tank as water seeks the lowest point and stirs up during vibrations. The real for water is to clean the whole fuel system not just part of it.

Note these carbs are on the lean side in the first place so it doesn't take much to screw up the running.

 

[mpqualdie]

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.

My thought is,, if it runs fine when they are engaged but surges up and down when disengaged it isn't a fuel problem. The clutch to engage the blades is most likely a electrical clutch. It is possible there is something wrong with the clutch or the harness. I repaired a Cub Cadet one time where something struck the clutch and damaged the wire harness to it making it short out. It kept killing the motor and then catching back on over and over. So it was like turning the key off, then back on before it completely stalled.
On the fuel note, you should only be using "non-ethenol" gas.

 

[mpqualdie]

Come on guys read the whole dang thread. JD said it was water in the fuel on in post 30. Most likely in the carburetor fuel bowl. Doesn't take all that much either nor does it takes that much in the fuel tank as water seeks the lowest point and stirs up during vibrations. The real for water is to clean the whole fuel system not just part of it.

Note these carbs are on the lean side in the first place so it doesn't take much to screw up the running.

Then why would it run good when the blades are engaged, but not when they are off?

 

[StarTech]

Look ethanol fuel use is Okay. I been using it for a very long in all my equipment.

Then why would it run good when the blades are engaged, but not when they are off?

Because these engines runs off the idle ports when off load [Called high idle mode]; therefore, any restriction the idle mix system will cause them to surge. These engines only uses the main jet when loaded by the deck.

I even had to repair one Nikki clone where the manufacture put too small of idle mixture jet. Even though the carburetor had an idle mixture adjustment screw the jet was simply too restrictive and prevent the screw from enriching the mixture.

 

[spetrilli]

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.

I use nothing but ethanol free premium in all my small engines, plus I put 5 to 8 oz of seafoam in every 5 gallon fuel container before I fill it.

I got tired of rebuilding and/or replacing carburetors on my equipment due to the negative accumulating effects of ethanol blended fuel on carburetor based engines.

E10 or E15 may be fine for fuel injected engines, but is a death sentence for carburetors… period!!!

 

[outdoorpowermike]

Must remove carb and in ultrasonic cleaner, remove the air mixture screw also so after 15 minutes of cleaning use compressor to blow out all ports. Replace all intake gaskets or seals. This should fix surging problem, and adjust mixture screw at idle if needed.

 

[RevB]

I use nothing but ethanol free premium in all my small engines, plus I put 5 to 8 oz of seafoam in every 5 gallon fuel container before I fill it.

I got tired of rebuilding and/or replacing carburetors on my equipment due to the negative accumulating effects of ethanol blended fuel on carburetor based engines.

E10 or E15 may be fine for fuel injected engines, but is a death sentence for carburetors… period!!!

Bull****.

 

[RevB]

Bad Gas is the standard when they have no clue . .Put Champion plugs in it .

Champion plugs are the standard answer when they have no clue.