gt235 running rough

Thomas_77June 2, 2014

I was wondering if anyone here could offer me some advice on my tractor.I have a 1999 john deere GT235 with the briggs 18 hp twin.It's been running very rough recently,at idle the engine will surge and smoke sort of like the choke is partially closed but it is full open.When mowing at full throttle it sounds just as bad.If i throttle back to an idle speed too fast it will stall out.I changed the fuel filter and the air cleaner.I've run through several tanks of gas so it's not that either.If somebody has a tip for me i would sure appreciate it.

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I would venture to guess you have a dead cylinder.
Try running it with one spark plug wire disconnected (AND GROUNDED)
Alternate to the other one.
IF you have a bad cylinder, it won't run with the good one disconnected.

    Bookmark   June 2, 2014 at 7:59PM
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O.k bill,but how would i ground the disconnected wire?

    Bookmark   June 3, 2014 at 1:21PM
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A piece of wire with alligator clips on each end.
Or many other different ways utilizing a screw driver etc.
Do you have a wife?;)

    Bookmark   June 3, 2014 at 6:11PM
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O.k I tested cylinders,engine will run when either plug is disconnected.Air filter has been removed and i notice a large amount of gas running out through air intake after i shut engine off.Could the settings on the carb be causing a too rich condition?There is almost always excess smoke when i throttle up,and a slight hesitation like it could be getting too much fuel.Could something be stuck open?

    Bookmark   June 4, 2014 at 3:04PM
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Sounds like the carb is too full.
The needle/seat is likely leaking, allowing too much gas in the engine.
I would have thought it would either clear up at high speed or flood the engine at low.

I'd suggest downloading the IPL from the Briggs site for your specific engine, which you might also post the Model & TYPE for our information.

There's a good chance a piece of "crud" is preventing the needle from sealing off the gas flow from the tank.
Knowing which specific Briggs would be useful.
In a nutshell, you have to remove the carb bowl, float & needle and flush the fuel line for a couple seconds.

    Bookmark   June 4, 2014 at 9:40PM
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Knowing exactly WHICH Briggs engine we are talking about will determine your actions on addressing the carb.
If it is an Opposed Twin, the carb bowl is not removable, as the "bowl" is integral to the carb body.
But, the main jet can be accessed via a removable plug on the carb body, and the interior of the bowl and the float/needle/seat are accessed by removing the top cover of the carb.

    Bookmark   June 5, 2014 at 11:16AM
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JD GT235 used both a Kawasaki FH580V and a Briggs & Stratton 350777

When the OP resolves his fuel problem a good idea to check the vent hole in the gas cap and make sure that's clear.

    Bookmark   June 5, 2014 at 10:08PM
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350777= Vanguard Twin.
This engine has the typical removable float bowl configuration

    Bookmark   June 6, 2014 at 12:40AM
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