[TxCyclist]

Where are you buying your motors? I have a friend one with he mounted but it's very old and uses a basic setup with a spoke with teeth that grip the wheel. Pretty inefficient.

[47Steve]

Tecumseh has a durable 49cc 2-cycle engine -- used on little rototillers and other small equipment and small portable pumps. They've been around a long, long time.

Tanaka has several very good small 2-cycle engines -- a quality Japanese company that has great 2-cycle designs.

Search the internet . . . there are lots of bike motor kits out there. Avoid cheap chinese engines -- you have no way to know the quality of the components or of the metal used to cast the engines.

[coondogg69]

Would you recommend going to a garage sale and buying someone's old weed eater and getting the motor off of it?

[d57tbird]

I bought a RAW Chinese 2 cycle 80cc motor kit (66cc actual) off eBay for $120 with free shipping. comes with everything needed for the conversion of my 1953 Huffy Dial a Ride bike. I also installed heavy duty Worksman cycle rims with Atom drum brakes, and a double brake lever to actuate both brakes with right hand, leaving the left hand open for the clutch. I had to machine the sprocket and fab a larger mounting ring for the drum brake hub. Have not completed it yet or run the motor...will post again concerning performance of motor and any issues with longevity if any. Plenty of Youtube videos with kits like mine out there, so some must be running fine. I like the old school look of my project. Motor fit well with some modifications such as home made spacer block and longer metric studs from local hardware store.

[Neuromancer]

It has to get up to at least 70 for the flux capacitor to work!

[s2pyd]

I would rather get a really small motor that is 4 stroke, is this possible? 2 strokes seem to smoke and stink alot and if you have that on your bike in an inconvenient place your probably going to get smogged out

[JustJohnny]

You would have to get a little sprocket thing and weld it to the end of the motor shaft....... how much is a welding machine I can do that with?

[47Steve]

Originally Posted by s2pyd

I would rather get a really small motor that is 4 stroke, is this possible? 2 strokes seem to smoke and stink alot and if you have that on your bike in an inconvenient place your probably going to get smogged out

Yes, Honda makes a very small 4-stroke and it's a good engine. The thing I like about 2-strokes is their simplicity -- basically three moving parts (piston, connecting rod, crankshaft) vs. about 30 moving parts for a 4-stroke. There may be other good Japanese small 4-stroke engines by companies like Mitsubishi, Kawasaki or Subaru.

My 2-cycle moped has a catalytic converter in the exhaust pipe and emits no smoke and not much 2-cycle stink, either. I'm happy with it.

Tanaka has a catalytic converter on their engines, too, I think.

If I were going to build a motorized bike, I'd want to consider the sound quality and noise level of whatever engine I chose. Some of the engine manufacturers advertise that they are pretty quiet.

[47Steve]

Originally Posted by JustJohnny

You would have to get a little sprocket thing and weld it to the end of the motor shaft....... how much is a welding machine I can do that with?

Don't try to weld the sprocket onto the shaft -- sprockets wear out and must be replaced, and the welding heat to the shaft may melt the shaft seal.

[mothra]

Whats a good way to attach it then? Would a belt system with a torque converter work?