I am a complete noob to all of this. I have recently been wanting to build a gas powered bike to drive to work. I have a specialized 21 speed mountain bike to put an engine on. I recently found an old Tecumseh 3 HP engine that has a slogan of "Hi im weedy I like people but hate weeds". It also has a scary picture of some sort of Weed zombie. Any way I have no problem mounting it to the bike but my questions are about gearing. Is there any way I could use the gearingof the bike by adding a gear to the pedal crank assembly? The output shaft turns in a way that it has to be pointed to the left side of the bike so it would turn the tires in the right direction. Is there a way to make the output shaft turn the other way, like changing the pickups on the flywheel? Basically I want to be able to use my gears. Thanks
Weedy engine
- Thread starter daddyfredregill
- Start date
I dunno about the weedy but Sick Bike Parts has a Jackshaft kit which allows you to transfer output power to the opposite side to power a freewheel on your pedal crank. expensive but possible. lot's of others have done it and are happy with results. Good Luck!
At what rpm does your engine make power? How fast will you be cruising?
With that information, you will know what gear ratios you'll need. Two stroke engines love low gearing (higher numerically). Big four-stroke engines can get away with much lower ratios. In comparison, my 47cc 2-stroke cruises @ 17.72:1 in 7th gear, with 1st gear @ 46:1, while 212cc 4-strokers might like 8:1 in high gear.
Most fabricators use jackshafts and face the crank left. However, I've seen Midwestmayhem face his crank right side and use a serpentine-style chain system to reverse chain direction. Search for Midwestmayhem on this site for more info on that.
Good luck.
With that information, you will know what gear ratios you'll need. Two stroke engines love low gearing (higher numerically). Big four-stroke engines can get away with much lower ratios. In comparison, my 47cc 2-stroke cruises @ 17.72:1 in 7th gear, with 1st gear @ 46:1, while 212cc 4-strokers might like 8:1 in high gear.
Most fabricators use jackshafts and face the crank left. However, I've seen Midwestmayhem face his crank right side and use a serpentine-style chain system to reverse chain direction. Search for Midwestmayhem on this site for more info on that.
Good luck.
