Check out the original Stevenson specifications here - only a guide

From the excellent site - they also have a build list here - Please let me know if there's a problem with reproducing this plan here, & I will remove it

Josh says

I have had the pleasure of emailing with Virgil Exner, Jr., a man with much automotive design experience and a recent Cycle Karting enthusiast. He has provided a set of drawings he recently authored for two Cycle Karts that he would like some feed back on. Please take a moment to enjoy his work and comment as usual.
Click the here to view the full size pdf file.

Cycle Kart Drawings
Cycle Kart Drawings

A CycleKart doesn’t weigh more than 250lbs and doesn’t cost more than $1750 (in 2001 U.S. dollars, accounting for inflation.) Maximum dimensions are fixed at 98″ by 40″, the kart is powered by a 200 cc, 6.5 HP Honda GX200 motor that supplies power to the rear wheels via a CVT. These are only guidelines for 'racing' specs
More extensive specs and dimensions here

The Virgil M Exner designed kart above appears to be in danger of being very difficult to get in and out of, esp. if the steering wheel is not removable. It is highly recommended that you construct a cardboard mockup of your design before committing to plywood to test the fit. It is all to easy to construct a design which would be perfectly comfortable if only there were a way to actually get in it. You must remember, your knees (most likely) do not bend backwards, and there has to be more room allowed than you might at first thing to allow easy ingress and egress. A cardboard mockup can save you from wasting your time on a design that doesn't work or works less well than you would prefer.

Stevenson's drawings here

From the Yahoo forum site
Honda GX200 dimensions
Lindsey publications has a book that tells most of what you want.

I wonder if we should have a basic step list here with links to where the rest of the information lies?