Best Engine for Project

[GPhillips]

I have been working on a suspended kart project for use on 1/8-1/4 mile dirt tracks in the area. I know this question is going to open up a can of worms but I am going to ask any how, which ATV engine(s) should I bee looking at using for the power plant of this mini-racer? My original thought was to use a 400ex engine but I thought I would throw this out there for open discussion.

Thanks

[DirtDemon]

A 400ex engine is a solid reliable choice, but not the fastest motor you could use. If you want to stay air cooled, you might consider an '84 or earlier ATC 250R motor. If you don't mind going using a motor that uses a centrifugal clutch, an old Oddysey motor would be a good choice, they had 250cc 2-stroke motors in the '77-'84 models and 350cc 2-strokes in the '85 model, all were air cooled. An old air cooled snomobile motor would also be a good route, maybe you can fit a big twin cylinder in there and really make that thing hausl as*.

[GPhillips]

It had been brought to my attention that for the application we are working on that a water-cooled engine might be a better option than an air-cooled one. Also it has been brought up about using a CR500 dirt bike engine.

[Stoopidbot1]

You will need a counter-balance in the CR500 or you will have lots of vibration.

What kind of tranny are do you want? CVT or manual shift?

[DirtDemon]

CR-500 motors are the motor of choice for 500cc Outlaw Kart racing. It is a great motor, and make a ton of torque even stock form. I don't know how much of an issue the vibrations are in the kart. I would visit an Outlaw Kart racing forum and get some info from those guys. I do know that they make custom motor specific mounts for use in karts. Here is a link that shows the mounts, the ones on top, BM-500 are for CR 500 motors.

QRC Factory Karts: Engine Mount