rear sprocket size?

igore · #11 (**permalink**) 07-10-2009, 10:52 AM

this is a harbor freight engine 3600 rpm, this 52 tooth sprocket I found at a garage sale. maybe a tooth change on the clutch sprocket

matt167 · #12 (**permalink**) 07-10-2009, 11:15 AM

Quote:

Originally Posted by Bikeguy Joe

Don't forget the china engine has an internal reduction.

yea, I know, I'm just figuring on what a stock 44 tooth can do, and going from there... as far as the 3hp engine, it'll have about 4 ft/lbs of torque without gear reduction. enough to get up most hills without too much gear

matt167 · #13 (**permalink**) 07-10-2009, 11:15 AM

Quote:

Originally Posted by igore

this is a harbor freight engine 3600 rpm, this 52 tooth sprocket I found at a garage sale. maybe a tooth change on the clutch sprocket

that would decrease your torque..

igore · #14 (**permalink**) 07-10-2009, 11:23 AM

on a 26 inch bike I wonder what speed it would go??

xlite · #15 (**permalink**) 07-10-2009, 11:37 AM

Quote:

Originally Posted by igore

this is a harbor freight engine 3600 rpm, this 52 tooth sprocket I found at a garage sale. maybe a tooth change on the clutch sprocket

I can tell you the HF 80cc needs at least 80-90 tooth rear and disable governor to get reasonable top speed.

igore · #16 (**permalink**) 07-10-2009, 08:29 PM

found this calculator

Speed Calculator For Go Karts and Mini Bikes