rear mount engine help

[pwd847]

Hey all, about 12 years ago I built an 80cc 2 stroke on some dumpy walmart bike. It was great. Now I'm back at it and wish to try a 4 stroke kit this time. In IL if I keep it under 20mph, I can be 100% legal on the road (got a DUI many years ago). This time around I want to try a rear mounted engine.

It just seems safer, not being in between my legs and all that. Also the 4 stroke kits often require replacement cranks and I'd rather not mess with all that.
Any suggestions on how to accomplish this?

I've looked online and I can't seem to find any mounting kits other than this:

4-Stroke Rear Engine Mount Full Assembly Kit Motorized Bicycle.NO ENGINE NO ENGN | eBay

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This is the bike I just ordered:

https://www.amazon.com/gp/product/B07LCGLW9G

I got the 29" frame single speed.

I'm also considering putting a different sprocket with more teeth on it to slow it down. I weigh 250lbs so I need to see how it handles with the stock build first.

Any help or advice i appreciated!

 

[Will'smotobikes19]

Staton inc friction drive kit is $122 but alot of people don't like the tire wear. The golden eagle kit is $700 so you probably don't want that. You can fab something. I have a 49cc 2 stroke on the golden eagle kit its almost too powerful as the belt has been getting damaged. Either it's too powerful or the spring was worn out. Definetely goes faster than 20 I'd guess almost 40 but the engine is screaming.

 

[Will'smotobikes19]

You might like this too. https://www.bikeberry.com/bbr-tuning-38cc-4-stroke-rear-axle-engine-kit.html around you if there's any hills that single speed with a low power motor will suck though. I have a 35cc subaru motor (4 stroke) and I go about 5 mph up a hill and that's why I took it off.

 

[pwd847]

I'd rather get a 49cc and adapt it to be able to mount it on the rear. I used to be a welder, but right now I only have a cheap $100 Menards welder. Maybe I can do it in a year when I graduate and start making the big $$$. Also I expect to have my drivers license within a year so then I'd be able to do 30mph, because that counts as a moped (which requires a drivers license).

 

[JerboaJohn]

a decent rack first, most are aluminum tho but if you look at pics of them, maybe you could copy the basic setup in steel? or similar to this: this is the Staton kit how it looks. all you'd need to do is have solid support for a regular 4 stroke mount plate down to the axle area, and forward to the seatpost. no welding if you use strong bolts. in the Staton kit, they use a reduction drive and power is offset to the pedal power side, but you don't have to do that. simpler might be a belt drive with a sheave on the wheel for left side drive
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