Top ends are all the same... had a little typo action going on in that last post and I just now caught it...
maybe just a touch more low end torque, but both the 66cc (38mm) and 69cc (40mm) perform close enough to the same that it's hard to tell the difference...
Thanks for the info, just curious as I am steering away from 2-stroke best I can.
4-strokes and electric are my thing now.
So 3cc in an actual measured more is pretty much like calling them 80cc's.
A bigger number with little benefit.
Not so with 4 bangers and electrics.
The numbers are all true and more is better.
I just tried out my first 53cc HS 144F-1G direct drive build.
Only 4cc more than the common 49 but you can actually feel the extra power exactly where and when you need it.
As for electric, well, easy for me, I am a certified electronic engineer and know exactly what the numbers mean.
Power (Watts)=Voltage x Amps.
In the case of batteries it's not the total amps they can burst, it's how many amps it can maintain and the rated Watts for an hour measured in Ah (Amp hours).
Sorry I wandered off topic, just built an electric with a battery whose claims were no different than 2-stroke vendors call 66's 80's and didn't do the job.