How do I correct engine surging?

[Alligator]

Ok, I have a John Deere LA115 Mower. It has about 125 hours on it and I have maintained it well until last year when it sat outside for the entire year. I moved and just had no place to put it. Now, it starts ok but the engine revs and slows at idle or under no load. When I engage the mower, the engine calms down and maintains a steady rpm. It has the single cylinder brigs engine. I know its one of the cheaper made lawn tractors. But, I really like it and would like to fix this issue. Any advise?

I have put a link to a video here that shows what it's doing: How do I fix this? - YouTube

 

[davesl708]

Hi. Welcome.

Sounds like you may have some bad fuel. Are you using ethanol in it?
My first suggestion would be to add fresh fuel and run some Seafoam through it.
May be crud in the carb.

 

[kencunningham]

I agree on the seafoam, also check governor linkages for free play and lube as necessary.

 

[aircommuter]

You may end up taking that carb. off and cleaning it, the gas with the alchohol in it absorbs water, then when it sits you get phase separation. That can even destroy your carb. due to the water corrosion.

 

[Alligator]

I agree on the seafoam, also check governor linkages for free play and lube as necessary.

Thanks. Please forgive my ignorance. What is sea foam and where do I get it.

 

[smstonypoint]

Available at Walmart, auto parts stores, etc.

Steve

 

[Alligator]

<img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=471428"/> Available at Walmart, auto parts stores, etc. Steve

Thank you! This is my first time using tractor by net and I have to say. You guys rock.

 

[orangeandgreen]

Instead of dumping "snake oil" into your engine, why noy do a little trouble shooting and determine what is actually wrong with it then fix the problem. The two most common issues that cause surging are governor problems (usually static adjustment) and fuel restriction in the carb(lean condition), which is by far the most common.
With the engine running, pinch the linkage that goes between the governor and carb and hold it still. If the surging stops, you have a governor problem. If the surging continues you have a lean condition.
Governor problem - Consult engine manufacturer literature for "static governor setting procedure" You didn't mention if you have a Briggs or a Kohler.
Carb problem - Start with fresh fuel, if it still surges, remove and clean the carb paying attntion to all the little parts and how they go together(pictures really help here). Use the wire from a bread tie to gently clean the inside diameter of the main jet and idle jet.
If replacement parts are needed, make sure you write down the numbers from the engine so your dealer can get you the correct items. If Briggs, Get the Model, Type, and Code from the valve cover. If Kohler, I think it is Model and Spec. that you will need.

Good luck

 

[Alligator]

Instead of dumping "snake oil" into your engine, why noy do a little trouble shooting and determine what is actually wrong with it then fix the problem. The two most common issues that cause surging are governor problems (usually static adjustment) and fuel restriction in the carb(lean condition), which is by far the most common. With the engine running, pinch the linkage that goes between the governor and carb and hold it still. If the surging stops, you have a governor problem. If the surging continues you have a lean condition. Governor problem - Consult engine manufacturer literature for "static governor setting procedure" You didn't mention if you have a Briggs or a Kohler. Carb problem - Start with fresh fuel, if it still surges, remove and clean the carb paying attntion to all the little parts and how they go together(pictures really help here). Use the wire from a bread tie to gently clean the inside diameter of the main jet and idle jet. If replacement parts are needed, make sure you write down the numbers from the engine so your dealer can get you the correct items. If Briggs, Get the Model, Type, and Code from the valve cover. If Kohler, I think it is Model and Spec. that you will need. Good luck

Thank you. The machine has a Briggs engine. This is more in line with what I expected to hear. I've just never done any governor or carburetor work. I'm going to try your steps and see how it goes. I'll post an update after the weekend and we'll see where we are. Thank you for the advise.

 

[kencunningham]

Seafoam is not snake oil, that is unless snake oil is good for cleaning carbs and making intake valves clean as a whistle. I have used it for years, every time I have a engine that has set too long and doesn't want to run right, it has worked. Snake Oil, LOL!