Wednesday, April 15, 2009

What Is Wrong With My Go Kart? The Engine Runs But It Doesn’t Move.

“I have this go kart and it suddenly doesn’t work. The engine works fine, the clutch appears to be mounted correctly, but the go kart does not move. What is wrong with it?”

Typically a clutch does not suddenly stop working…but in my recollection, yes they do.

Unless you are looking for the symptoms, you will not catch what happens to centrifugal clutches.

What occurs is that over a period of time the clutch actually starts to fall “shear itself” apart. This happens typically if the clutch is not mounted to the engine tightly. The slop between the engine and the clutch will impart shock loads into the clutch causing the driver to shear apart.

The weight slinger is a pressed metal plate with tangs in it. The tangs correspond to teeth on the clutch driver. Typically the pressed metal plate is actually harder material than the clutch driver, so the tangs on the driver become sheared.

As is the case in the clutch that pictured here, the tangs are on their
last legs. What occurs is that the tangs become sheared off completely, and the engine will free wheel and the clutch will not transmit the load. (This particular clutch was getting ready to fail...fortunately I caught the problem and replaced it.)

To fix this, a new clutch is required. I have welded some in the past, but I would not recommend that seeing the clutch really is on its last legs.

The front side for example is really getting pounded as well. The teeth on the sprocket and the bell housing are getting ready to let go.

The reasons for these failures is two fold:

- Sloppy clutch mounting to the engine shaft

- Heavy loads being driven and the clutch slipping quite often (shock loads during engagement occur, which impact into the teeth of the sprocket and the bell interface.

So yes, the clutch will suddenly stop working, I remember how frustrated I was when I discovered this a couple years back.

Bottom line: check the clutch and see if it is broken.

1 comment:

Shannon said...

I have a Murray go kart with a 6.5 B&S Engine. The problem that I am having is that when I pull to start, the belt engages and the engine won't idle. What is wrong?