First Venture into a 4 Stroke....need some opinions

H

hombremosqa

Member
so, ive been running a 2 stroke that i bought from bikeberry, and its had been running fine until recently. so after much consideration, and debating with the wife, i decided its time i find myself a 4 stroke to use. (lets face it, pull start is easier than killing yourself trying to get the damn friction drive started on my 2S)

so, ive been shopping around locally, and have found a few options. BUT size, and adaptation has come into play.

Harbor Freight offers a small 4stroke that runs about 100 bucks.
- Harbor Freight Tools - Quality Tools at the Lowest Prices
its small enough to use on my frame, (although im sure i would need a mounting plate or something)
but im worried about the crankset. i think its a bit too wide for what im putting it on.

BTW, I really, REALLY do NOT WANT to rack mount it since it raised the CG of the whole bike. lower is better in my case.

locally, i have found a few other options as well, but its still around the same size. I did manage to find an older briggs and stratton, and ive heard it run. it was just rebuilt.

Give me some info guys!
 
The two major obstacles that you run into with the 4-stroke motors available are 1) accomplishing the amount of total reduction necessary to operate your bicycle and 2) The overall width of the motor and drivetrain and keeping the pedals/crankset operational. The Chinese 2-stroke motors have a built in primary reduction of approx. 4.2:1 Non of the 4-stroke motors that I'm aware of have this reduction built into the motor. The folks that offer/build kits using 4-stroke motors provide some type of primary reduction gearbox/drive to provide this reduction. If you spend some time reading thru the various posts in the 4-stroke section of this forum you will find a great deal of discussion about the various gearboxes and other drivetrains available. The two most common 4-stroke kits available the Grubee and the HOOT both measure in at 9 ins. wide +- I think the new EZ kit is pretty close to the same.
The motor you linked to from Harbor freight is closer to 12 ins wide. Its going to probably going to require custom fabrication to get a crankset spread wide enough to clear 12 ins.? If your not going to go the kit route spend some time here searching things like jackshaft set ups and CVT reduction boxes.

ocscully
 
well, as far as width is concerned, i was already thinking about just doing away with the pedals, but some here would consider that heresy. I had already figured if i mount the engine on the frame, i would need a wider crankset. i remember seeing the old OLD indian motorcycle footrests (the kind that looked like brush guards) and thought about doing something similar.

as regards the gearbox, i have never seen one installed. any pictures available?
 
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