Honda Spree and Elite 50 Forums

Title says it all guys. I want to make the biggest, fastest, most death inducing motor I can. To boldly go where no scooter builder has gone before. I got some measurements from the 5 or so stock cylinders I have, lets see if we can find something that fits with some port or case work, maybe a spacer under the cylinder.

Factory Specifications:
Bore: 55mm
Stroke 42.4mm
Compression ratio with stock head 6.7:1

My measurements:
Bolt spacing across (center to center): Aprox. 55mm
Bolt spacing diag. (center to center): Aprox 81mm
Cylinder sleeve into case outer diameter: aprox. 62mm

I have photos of the stock cylinder and head on request, you can dm me and I can email them or share over google drive. Let me know what questions you guys have and I'll try and answer them the best I can.

First thing to do is cut the head because that little compression is useless for making horsepower. I would think 5 or 6mm would up the compression enough to make some real horsepower. At least that's what I'm doing to my Aero 80 which has a 6.8:1 compression ratio.