Engine Recommendation

[CIncinnati]

My preteen son wants to convert his new 26" Schwinn Ranger bicycle to a moped. What is the best way to restrict top speed of a conversion? He weighs about 140 pounds.

He wanted a 66/80 CC kit. But in researching this, I found the 48CC Skyhawk GT2B 2 stroke kit. I am leaning toward this kit. Obviously less displacement is less power. I was thinking of a top speed of about 12-15 MPH.

How is the reliability on these engines?

Do you have a different recommendation?

 

[butre]

get a 56 or so tooth sprocket. it'll have enough low end power to have fun on but not enough top speed to get seriously hurt. stock engines often don't have any pulling power down low

 

[butre]

just make sure you know where he is when he's riding. a lot of kids are pretty reckless and motorized bikes are under constant scrutiny because some kid decides to ride at night with no reflectors or runs into traffic while trying to outrun the police.

also, just having a rear coaster brake isn't enough, you'll want to fit front brakes too. a front rim brake is better than nothing but a disc or drum is ideal.

you could limit the throttle position by putting a limiting screw in the throttle mechanism, that will help contribute to a longer engine life as well

 

[crassius]

check local laws about age for riding on streets

 

[motorbikemike45]

If I were you I would use a staton-inc.com friction drive kit with the Subaru Robin 25cc 4 cycle engine. Order the drive kit with the smallest drive spindle available(lowest gear ratio to restrict speed). It is more reliable, simpler, and QUIETER than the 2 strokes. He probably shouldn't be allowed(Likely it is illegal) to ride it on streets and roads. The lower drive ratio of the smallest drive spindle will give it more torque to use off road.

 

[motorbikemike45]

The staton friction kit is more expensive, but the extra bucks and quality means dad won't be spending all his spare time tinkering with a chaep, poor quality kit.

 

[Purple Haze]

Don't do it, it's illegal in most states for anyone under 16 years old to ride on the street on a MAB. Ohio requires anyone riding a MAB to possess a valid drivers license.