Modern Vespa

They look faster than the modern 250/300s.


sounds like 2 stroke... not sure

Drag bikes. Sure they're fast, but as highly-tuned two strokes, they're tuned to eat themselves.

There racers.Kitted 2 strokes.Looks fun ,right.

I used to race 2-strokes (Bultaco & Yamaha) motorcycles. The joke with 'Tacos was that you bought pistons in a six-pack.

Tuned 2-strokes do "eat themselves" as Jess said. They also tend to have very, very, very, very, very, very, very, very, very narrow power bands, more like a switch than a throttle. Fine with a close-ratio gearbox on the track, not so much on the street.

P.

They might not last long but they sure are a lot of fun!

It's also a lot smaller than a larger 300.

Curious, what speeds do they reach?

mental ..........

madness .........

Cool video, a little faster than my ET.

Jess, don't you sometimes tend to think your CB bike was tuned to eat itself? I know I personally believe my kitted out GT was tuned to eat itself. Maybe even my GTS... but thats YTBD.

Lambretta with a 225 ts1 90mph

Nah. The CB bike wasn't even all that ambitious. It did fail, but nothing especially exotic -- I just blew a head gasket. Could have just not managed to torque down that corner of the top end correctly. It certainly didn't eat itself.

My GT200 land speed bike was a bit more ambitious -- we had to make up the relief cuts in the piston from whole cloth, because Malossi couldn't be bothered to spec it. Then I had the piston coated with some exotic coatings, just to add some more uncertainty. But even that wasn't really tuned to eat itself -- no exotic cams, nothing weird. I have this sneaking suspicion, though, that the GT200 might be more susceptible to that kind of failure from extreme tuning (like yours did). Or maybe it's just a weakness in the oil pre-screen. Dunno.

I'm now rebuilding my CB bike, and there's really no damage that I can see. I'm being meticulous, and lapping the valves and stuff, but aside from dirt and grime and gasoline additive buildup, there was nothing wrong with the head or the cylinder.