4 stroke 50cc?

[lukerogers94]

im building a mini chopper, and im looking at buying a 4 stroke 50cc would this be enough to push me around at say 40km/h?

 

[Affair_driven]

Going to need at least double that size.

 

[mike75925]

with the right gear reduction maybe, after all, it's not like you said 40 mph.

 

[Affair_driven]

40kph = 24.86mph
50cc won't cut it. Reduction will make things worse.

 

[ed1380]

why 4 stroke?

 

[mike75925]

some of these two stroke 49cc's run pretty fast. with a four stroke seems more readily done. with the added torque, you could run smaller wheel sprocket and still have a decent acceleration. right?
all these older mopeds and small motos run i would say a good 30. depending on his engines tune package.

 

[oscaryu1]

49cc 2 stroke would do it.

If it doesn't, add on a CNC lightened and balanced flywheel, rockit 10 degrees advanced timing key, full circle crankshaft, Black Widow 3 stage reeds, big bore kit, port and polished cylinder, NGK spark plug, 2 shoe adjustable racing clutch...

Yeah.

 

[mike75925]

that's alot of stuff for 30mph. shoudn't you get like a hundred out of that? ballpark, idk.

 

[Kaptain Krunch]

that's alot of stuff for 30mph. shoudn't you get like a hundred out of that? ballpark, idk.

Are you serious? its 49cc, you can only go so far...Even with all that stuff in the end there is no replacement for displacement.

 

[mike75925]

true displacement is the easy way for power, aprilia makes a 50cc that does 70, granted with a six speed tranny

 

[lukerogers94]

80cc?

do you think that a 80cc would cut it?

 

[mike75925]

i've had a few 80cc dirtbikes, with four and five speed gearboxes, they topped at 45/48mph and they were about 3/4 life. if thinking bike engine, yamaha's yz85, will come up in all six gears, and top 75mph with a 145lb rider. next would be the kx80 expert.

 

[lukerogers94]

why 4 stroke?

not really by choice but it was what i could find, but anyway wouldnt a four stroke sound better on a chopper. anyway i did some more searching and i might be able to get a 5 horsepower or an 80 cc they would push it around much better.

 

[mike75925]

if the 80 has a tranny yes, it would be the fastest.