[kliff]

Like ckau said, scooters and buggies are VERY different animals, if in only their operation.
For the most part, a buggy is on and off the throttle continually on trails.... the river bed at St Joe is an exception to the rule.
Most scooteristas pin the throttle and hold it, mile after mile, after mile, in the daily commute, or weekend pleasure ride. Gearing becomes a key to valve life, by keeping rpms under 7500. With gearing, and more importantly variator, a relatively stock (uni, exhaust, & jets) can pull a 250lb passenger at 57mph, at or about 7300-7500rpm. The guys that go for unlimitted CDI's and shot for hiway speeds without this driveline tuning, usually end up cruising at 8>9000rpm, mile after mile, and seldom more than 1>2K miles on the odo, before a valve spring gives up, and the top end is lost. My personal scoot runs out at 57mph/7400rpm, with 1500 clutch and torque springs, 115mm variatorand 14gr DRP sliders. But remember there is NO further reduction beyond the gearbox. The wheel mounts directly to the axle shaft, and is about 18" tall. It and I together only top out the scales at 475lbs, frontal area(wind resistance) could only be about 1/3 that of a buggy.

If you want top speed, the gears and sprockets are out there, but at what cost? My scooter is set up to be comfortable doing what I do, cruising at 45-50mph, with a little left on top, and a stock rev limitter in place.

My buggy will be set up for tight wooods, a cruise speed of 30-35, top end maybe 40, NON regulated CDI

Different worlds, different requirements. Build what you want, cross over if you wish, but remember 5 minutes of WOT, 8000rpm+ on a scooter, has done as much wear and tear on a set of valve springs, as probably a season in the woods with your buggy, even though it may have seen some 9000rpm+ "bursts" that never lasted more than a few seconds.

Buggies can get away with lighter variator weights, and non-regulated CDI's because of the area of operation, they are used in. Up and down on the throttle, 2000rpm> 9500rpm for a few seconds, back down to 4500, yadayadayada, that's what these things do best, and live the longest doing, as long as clean oil is in the sump, the valves are adjusted, jetting is spot on, and intake filtration is at a premium.