problems with a Craftsman lawn tractor

[Donald]

Helping a friend with her maybe 10 year old Craftsman lawn tractor. I would say its 18-20 HP. So two probloems:

1) The engine starts and runs at a very fast RPM. The throttle changes the speed slightly, but even with the throttle all the way to slow, its still going at a high RPM. I assume the governor is making the engine go fast, but have no idea why. I have pushed the linkages around and they all seem free to move.

2) The engine does not sound good. I found it very low on oil and added about 1QT but that did not solve the problem.

 

[boraticus]

Throttle linkage needs to be inspected. The governor will control over-speed but should not have an impact on effective throttle range.

Don't worry about how it sounds unless the valve lash needs adjustment. If the engine has been abused, the noise might be just the way it is. Straighten out the throttle/engine speed issue and carry on.

 

[Donald]

OK, maybe I have the wrong name (governor), what gives the engine more power when you get into heavy grass for example? Isn't that the governor? When I move that part of the linkage the engine slows down.

The owner says it vibrates and sounds like it has no oil, but it does have plenty of oil now.

 

[40Deluxe]

I had same problem on my craftsman last summer,it had briggs 18 horse engine,and had same exact issues,the screws fell out of the throttle plate that hold it to shaft that is controlled by the throttle cable or control handle on dash.When the screws fell out the engine still ran but not very good,itore the engine down and the screws had went into the valves of the engine and one made it to the piston where it did a great deal of damage,this engine consummed a large amount of oil as well.Before any one says anything it was not making any unusual noise either.

 

[JTK]

If it's not what 40D says, It sounds like something has gotten jammed or is missing on, or around the throttle and/or governor linkage?

I'd start by working the throttle lever up/down with the engine off and cold. Eye-ball how everything is moving and see if there's anything obviously wrong.

That area can be a mess of rods, linkages, levers and springs. I know If any of mine came undone in a big way, I'd need a clear picture to figure it out.

Specifically, what engine is this? Single cyl, horizontally opposed twin or V-twin?

You might be able to get close-up pics online.

Joel

 

[660mag]

Sounds to me like the internal governor lost one of its weights. You could try to reset the gov arm. Loosen the nut, hold the arm in wot, and twist the gov shaft all the way clockwise. If nothing changes, try turning the gov shaft all the way counter clockwise. If nothing happens after that, and you do have a gov spring in place then the internal centripetal governor has failed(come apart) due to a lack of lube. Good luck.

 

[Donald]

Its a single cylinder vertical shaft engine. When I move the shaft that is directly connected to the throttle on the carb (but only indirectly to the Fast-Slow control, it will slow down, but when I let it go it seems to want to move making the engine go much fast.

 

[660mag]

Follow the linkage on the throttle shaft of the carb away from the carb to the point where it connects to the engine block. This is the governor arm, and where your attention should be focused. Follow the instructions in my above post, and if it does no work, then it has a failed internal governor. Not uncommon for an engine run low on oil. Air cooled engines are more reliable than liquid cooled, but have very little room for error when it comes to cooling them. Oil level, and a clean air cooling system are paramount.

 

[JosephHarmon]

You fail to describe the engine make/model. ???