Spooky Tooth Cycles sells all kinds of special bikes. Mostly bikes with gas and electric assist motors.
Their gas motors are 2-stroke but quieter than usual. They’re 48 or 80cc in size and get 150mpg and can go 40mph in the larger size.
Their fully equipped bikes cost about $500 but you can buy the engines on their own for $250 and strap them on yourself.
A sweet thing is that they have a lively forum and support group full of advice-giving folks.
I wonder if they’re putting them on dual-sus mtbikes yet. –Make a light, snappy dirtbike! My bro says they’re NOT SO torquey. But that they’re darn fast on the road.
…Be careful with these Rods! The Heat is out for them! “Where’s the law, Drew?!” It’s hard to imagine that cops could care less about such things, in this day’n’age of many cops driving “loud pipes save lives” bikes themselves. Well, keep your nose clean and use common sense: the faster you go the more you better obey all the usual rules (no cutting, etc.).
https://www.spookytoothcycles.com/content/view/165/153/