The problem with a vertical engine is routing the power from the engine to a horizontal wheels on the go kart. Typically the standard method for transferring the power on vehicles involves a gear box. For example on a lawn tractor the gearbox is designed with a pulley on the top of the gear box. Additionally, because the main purpose of a riding lawnmower is to cut grass, so the vertical engine layout works very well driving a mower deck.
The temptation comes in to play to use the gear box in the gokart and keep the unit simple that way. Unfortunately, it is not really simpler, but more complex, not to mention unreliable.
Additionally, I would strongly steer you away from using a riding lawnmower gearbox for the following reasons:
– Width Of The Rear Axel System Is Too Narrow
– Gear Boxes Are Not Designed For High Speed As In 20+ Mph.
– Gear Box Engagement Requires Belt Tensioning Devices.
– Switching Gears On The Fly Is Not Possible Without Good Engine/Gearbox Knowledge.
Width of the rear axel system is too narrow. The width of a gokart drive wheel layout should be relatively speaking wide: 36″+. Riding lawnmowers are under that width and will pose a difficulty in powering the rear wheels. Mounting the gearbox is another issue that requires special bracketry that would need to be fabricated and mounted to the framework.
Gear boxes are not designed for high speed as in 20+ mph. This is a serious consideration, especially with gear boxes that do not require lubrication and do not have roller bearings.
Gear Box Engagement requires belt tensioning devices. Typically, the gearbox is activated by tensioning the belt.
Switching gears on the fly is not possible without good engine/gearbox knowledge. The gearbox on a riding lawnmower does not have synchronizers with it, so the gearbox must be completely idle or still for the gears to be switched.
Actually, in order to get gears to mesh properly, both the mating gears must be in the same position. This can be accomplished by running the gears at the same speed, but this does take some understanding of how a gear box operates. Unskilled drivers will have extreme difficulty getting the gearbox to work. More than likely, the gear box will be destroyed in a relatively short period of time, if shifting is considered on the fly.
Bottom line is that the transaxle is designed for tractor use and has some limitations. There are some better options that are lighter and more user friendly.
Next time other vertical engine drive systems.