Lawn Mower Man
How to Use a Lawn Mower Engine for a Go Kart
Lawn mower engines are a dime a dozen, you think to yourself. Surely there's a way to use one and save some cash... You already know that go karts traditionally use horizontal mount engines — for good reasons we'll discuss. But if you're committed to being a nonconformist let's figure this thing out.
Lawn Mower Engines
A lawn mower uses a vertical shaft motor. It's designed to be mounted and used in the vertical position. This can not be changed without a lot of work, maybe not at all.
Repositioning to Horizontal
The mounting face for the motor is generally on the same side as the shaft, so you'll first need to design a mounting bracket to hold the engine in the horizontal position.
Now you'll realize that carb is turned on its side. You'll need to drill and tap new mounting holes.
If you open the crankcase, you'll see that the oil slinger won't be in the oil supply. You'll have to figure something out to ensure the engine stays oiled.
Those are at least two giant problems that you'd face with this "easy" solution.
Now let's examine using the engine in the stock configuration.
Using a Lawn Mower Engine Without Repositioning
If you decide that changing the mounting design is too involved, then the other option is to use the motor as normal, and get the vertical shaft's power transferred to the horizontal shaft's plane.
For this, you'll need to get under a riding mower and examine how they do it closely. Probably you'll want some kind of gear box to do this. We might say "use the lawnmowers!" but then again, it will need to be very heavy-duty to withstand the off road driving that you're considering. So you'll spend some time beefing it up.
We scored a free lawn mower recently, and are tearing it apart to try to find a good way.
Share Your Ideas
Admittedly, this section is here just to float some ideas around. We have little intention of trying very hard to do this ourselves, because using a horizontal mount is simply much easier. But — if you're willing to try it, document the process! Let us know how it goes, and have your own project published on the site. We'd love to help you show off!