80cc engine, is it really 70cc?

[holdenrodder]

ive been looking at engines on ebay, and all the kits look identical to me, but i have not yet got an eye for the diffrences between them. but ive been wondering weather the 80cc is really 80cc or 70cc? also, are A80s really a better quality? whats the biggest cc's they come in? and what diffrent heads are there, whats the diffrences and how do i tell between them? just after a bit of expertise before i go and buy an engine at random. thanks!

 

[The_Aleman]

Most of them are between 66 and 68.5cc, with the majority about 66cc. Only way to be sure is to measure the bore and stroke.

One thing you can be sure of, any seller who advertises these as 80cc, 5-6HP, and 150MPG is apt to lie to you.

There are several factories making them, some have slightly different configurations. Any way you go, you'll be playing the Chinese lottery.

 

[holdenrodder]

haha, then i geuss i better suck it up and buy a ticket, haha

 

[relaxxx]

I've achieved 150mpg. But with a 32 tooth rear sprocket and just putting along and coasting down all hills. This is probably a 66cc (was advertised as 80cc). The 32 tooth really lowers rpm's and fuel consumption. I'm also 6' 245lbs so someone lighter should be able to go farther. On one tank of gas, which I believe is half a gallon, I traveled over 120km or over 75 miles. When I got home I think the only gas left was in the fuel line. I also lost my tensioner and a couple spokes that day.

 

[The_Aleman]

With a 66cc, I've averaged 80-90MPG @ near constant 30MPH using a 34T rear sprocket, and that's with pedaling a 52/11 gear. I'm about 6'4" 230 and pedal a lot.

With another 66cc and stock 44T gear, I averaged about 80-90MPG @ 25MPH, a little too fast to pedal a 52/20 gear. The worst mileage I have got was 75MPG.

Gas mileage is variable of course, what I'm saying is averaging 150MPG over the long run with a stock kit setup is very unlikely.

 

[relaxxx]

30MPH is near wide open for me, my max is probably 34MPH (55km). I will burn gas much faster at top speed. When I putt along at 15-18MPH (25-30km) is when I see huge mileage.