Honda Spree and Elite 50 Forums

Greetings:

Stock bore for an Aero is 41mm nominal. (40.995 or somesuch - it's in the Service Manual). SA16 Elites used a longer stroke and smaller bore to get the same 49cc displacement, but I remember reading that stock was smaller than 40, like maybe 39mm?

oversized piston will have .25 or .50 stamped on the top i beleive

Spree pistons are 41mm. 10mm wristpins means it's an early design, Dio's have 12mm wristpin.

My bet is an early 83/84 Aero or Express. Both use 40mm piston and 10mm pin.