Adjustable two stroke exhaust?

[GreyGhost]

Ok, this is clearly not a motorcycle but it wouldn't be hard to incorporate something similar (left throttle to control?). Probably not that useful in lower gears as there is too much going on and not enough time/skill to properly manipulate but in higher gears changing the pipe tune to match rpm could noticeably increase power. Anyone know if it has been done before?

1M views · 314K reactions | @europeanpowerboatracing with the start of #4cylinder 500ccm #twostroke The pipes are manually controlled by drivers pedals and change to adjust for #rpm range . . #racing #race #boats #engines #speed | Car Builders

@europeanpowerboatracing with the start of #4cylinder 500ccm #twostroke The pipes are manually controlled by drivers pedals and change to adjust for #rpm range . . #racing #race #boats #engines #speed.

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EDIT:
Although not the best form factor for a bike, a flat 4 500cc two-stroke is pretty cool. Anybody know anything about it? I assume 4-125's put together by an evil genius?

It looks like a flat 4 bike has been done before. They went with cylinders aimed at wheels. Check out this ridiculous belt routing.

 

[bitzz]

That's a Kim Newcombe bike.
Quite a story. Konig outboard motor shoe horned into a moto frame. He almost won the 500 world title on it

 

[bitzz]

The outside belt is a water pump, the toothed belt drives a rotary port valve disc on the top of the motor. The 4 cylinder shared 2 carbs/intakes (down draught Webbers) and 2 pipes, AMC (Norton/Triumph) gearbox.
It's a pretty cool motor. My cousin raced unlimited outboard hydro planes in the '70s with a Konig.

 

[Mad Mike]

I love Allen Millyard's 2 stroke build videos. He makes it look so easy that I think about making my RD125 onto a 4cyl rd 250 from some stuff I have in the garage. I havevthe tools to do it, l never will, but I like thinking it through.