Lawn Boy 10686 Engine Bogging Down

[train42]

Hello,

Lately my Lawn Boy 10686 with sens-a-speed has been acting up. When the drive wheels (rear) are engaged, the engine bogs down severely. If I push the handle up slightly so that the rear wheels are lightly touching the ground it runs fine. I don't have any issues pushing the lawn mower when the engine isn't running and pulling the lawn mower backwards also isn't a problem. Any ideas as to what the issue could be?

 

[bt3]

Hello,

Lately my Lawn Boy 10686 with sens-a-speed has been acting up. When the drive wheels (rear) are engaged, the engine bogs down severely. If I push the handle up slightly so that the rear wheels are lightly touching the ground it runs fine. I don't have any issues pushing the lawn mower when the engine isn't running and pulling the lawn mower backwards also isn't a problem. Any ideas as to what the issue could be?

I have had the same issue with my 680541 2 cycle and on my Snapper 4 cycle (Wisconsin Robin Engine). On a 2 cycle it can be the exhaust ports/muffler, carb issue, spark issue, or governor/wind vane issue. On a 4 cycle it often is carb, or governor.

It's usually fairly straight forward to diagnose. On my Snapper, a very heavy commercial industrial mower, I lost my drive mechanism finals years ago and have not replaced them. I decided to convert it o push. I look at it as a free workout.

 

[mechanic mark]

Lawn Mower Parts, Small Engine Parts & Much More! | PartsTree.com - Briggs, MTD, Toro, Cub Cadet, Husqvarna, Troy-bilt... Inspect belt for replacement, visually inspect all transmission drive parts. Remove rear wheels and inspect bearings for replacement.

 

[bt3]

Mechanic Mark is probably more on target than I am, but I did want to relay one specific experience with my LawnBoy bogging down just as you have described. Heavy grass, or engaging the self drive would bog it down. Heavy grass and engaging the rear wheel drive combined and it would stall out.

After a lot of fiddling I realized that the Governor Vane was not freely pivoting. Crud had built up beneath the Vane pivot point on the Carb and was not allowing it to move freely, thus no Governing of the engine. Carb Cleaner and Liquid Wrench sprayed into the Governor Vane Pivot Point finally fixed the problem after a season of issues with bogging down.

 

[mechanic mark]

Mechanic Mark is probably more on target than I am, but I did want to relay one specific experience with my LawnBoy bogging down just as you have described. Heavy grass, or engaging the self drive would bog it down. Heavy grass and engaging the rear wheel drive combined and it would stall out.

After a lot of fiddling I realized that the Governor Vane was not freely pivoting. Crud had built up beneath the Vane pivot point on the Carb and was not allowing it to move freely, thus no Governing of the engine. Carb Cleaner and Liquid Wrench sprayed into the Governor Vane Pivot Point finally fixed the problem after a season of issues with bogging down.

Great post bt3, good information, thanks for posting.