topping oput at 40MPH, 6hp tecumseh, series 30 TAV,

[Socal_machinist]

I'm hitting the wall at 40 MPH I'm running a 6hp tecumseh powersport, comet series 30 TAV, 12:72 sprocket set, 20" drive wheel. I have a homemade header and stock muffler.

 

[r_chez_08]

Have you removed the governor? If not that is the maximum speed you will get to.
I would say you have done pretty well out of the 6hp. If you want to go much faster you must make sure your kart is up to it, and safe enough should an accident occur.

 

[Doc Sprocket]

You may simply not have the power to go any faster. 6hp with 20" tires is pretty taxing. If you're actually hitting 40, you're doing well. It's probably time for a power upgrade. Hit a speed calc, and work backwards to see if you are actually hitting 3600RPM. That will tell the tale.

 

[r_chez_08]

3600rpm with 20" tires and 6:1 ratio with 1.1:1 overdrive would work out to be just under 40mph.

 

[Brandon1023]

How fast are you expecting to top out at with that set up? You're lucky to be getting the speed you're currently getting.