John Deere Lt133 surging

[tmjbegue]

The Lt133 was backfiring and difficult to start. Found gas mixed with the oil. Cleaned all that out, New oil, new filter. Replaced the carburator and fuel filter. Now the tractor surges at high speed and the cutters NOT engaged. Seems to run fine at a medium speed. It also runs fine with blades engaged at high speed. High speed in any gear and no blades it will surge.

Any thoughts or ideas would be appreciated.

TIA.
Tom B

 

[Deleted member 97405]

You have debris in the high idle jet of the carb. Usually with a machine of this age, I suspect the fuel lines and/or fuel pump may be deteriorating and putting debris in the carb. The pump and fuel lines after the fuel filter are suspect in this situation. Remove the bowl from your new carb and see if there is small black debris in it. If so, the carb will need cleaned and you'll need to replace the fuel lines from your fuel filter all the way to the carb. Replace the fuel pump as well, even if it's still working. Blow and flush out the metal fuel tube that crosses over the engine as well. This is the only way to eliminate deteriorating debris from getting into the carb since all this is after your fuel filter. Blame ethanol. It dries out the fuel system components over time, especially on pre-ethanol machines.

 

[Rivets]

You installed a new carb, was it an OEM carb or one you found on Fleabay or Amazon which says it will replace your OEM carb? Vast majority of the time I’ve found those cheaper carbs will cost you more than buying the OEM ones. There’s a reason you find them so cheap. Please post all your engine numbers so we have an idea of what you are working on.

 

[Deleted member 97405]

You installed a new carb, was it an OEM carb or one you found on Fleabay or Amazon which says it will replace your OEM carb? Vast majority of the time I’ve found those cheaper carbs will cost you more than buying the OEM ones. There’s a reason you find them so cheap. Please post all your engine numbers so we have an idea of what you are working on.

He's working on a JD LT133. They all used the same AM125355 carb regardless of the engine. But for argument's sake, the engine could be a CV13S or CV15S per JD's parts system. I agree on the Chinese carbs. They are totally junk and not worth the small amount of money they cost.

 

[tmjbegue]

I replaced with an OEM [expensive] carburator. I'll check for debris in carb bowl.
Engine is a Kohler CV13S.

 

[tmjbegue]

There is no debris in the carburetor bowl.
I'll go ahead and replace fuel line, clean carburetor and try again. Have to wait till tomorrow to take next step.

 

[StarTech]

Try doing a static governor adjustment and also make sure the minimum idle speed it set.

Slow Idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1700 ± 25 rpm
Fast Idle (Domestic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3400 ± 25 rpm

 

[tmjbegue]

Thanks.

 

[Hammermechanicman]

Before you changed the carb and before it leaked gas into the oil did the engine run properly at high speed? If it did then most likely the carb is jetted wrong. Pretty common on every AM kohler carb i have seen and on some OEM replacement carbs. Don't know what carb you have but if it has removable main jet swap the one from the old carb to the new one and see how it runs.