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There are 63mm cylinders for 54mm bolt spacing. Also found a 4v head that even uses possibly the same cam (y shaped rocker) so if I'm lucky I'll run my a9. The head fits on a 63mm bore with 54mm spacing. I do love an over-square motor, gimme all them rpms. It looks like it uses the same size gy6 valves just twice as many.

The bore is like 50 bucks for the jug, pison, rings, gaskets. The head is over 400 for the complete head and valve cover. So bore first, running the big valve head that came with my current 72cc setup

I am fully aware the crank is eventually gonna pop. Offerings to the gods of speed. Gotta look into something that can handle stupid rpms, like aiming for 12k. The kymco crank is high quality but I'm really pushing it with that giant piston. If I do upgrade I'd like to keep it at the same stroke, maybe go up to 200cc but idk.

Has anyone done this? Aside from boring/rotary grinding the case, what should I expect to deal with?

There will be a steel pan under the seat to protect myself from catastrophic engine failure shrapnel

Gonna make a new engine cover/cooling duct for the cylinder and probably get a fan with curved blades instead of the cheesy factory ones. Maybe a leaf blower impeller lol

I'll step up the carb too, running 22mm now, gotta figure out what size I want n get the jet kit

Heavily modified 72cc super 8 50r, looking to convert to standardized aftermarket 6 pin cdi's that flood Amazon. I bought a new 6 pin hardness for an easy plug in. I'm just not sure if the 8 pin was dc or ac stock in the scooter. It's a 2015 so I'm gonna guess ac. I think I'll have it running in a day but I'm hoping somebody has done this and can let me know if I need anything additional or hey if you could spot me a diagram that'd be great lol

The muffler has a cat built in, i chopped it off and fashioned a megaphone from an empty 88g co2 cannister, if you have access to a welder this is a great way to go, i shoot wonderful exhaust flames

I clipped the purple wire, i noticed a power gain for sure but i still have a rev limiter. At this point i can reach 37 mph before it starts popping and cackling. Im not sure what was interuppted by that purple wire but i can attest to a definite POWER change, NOT a TOP SPEED change.

biggest difference of ALL though, was a sneaky little restrictor washer in the intake manifold. Before removing i, i found that wide open throttle caused a bog, it was difficult to accelerate at the same pace as traffic, uphill was a challenge at 15 mph grunting like a depressed pig.
since i removed the washer, the engine starts easier, runs better, doesnt die at idle, and i can hold 30 mph up hill now

Next step is the variator boss