gas engines

[5speed]

i got 2 dyno single speeds with the big tire in the back,would like to convert on to gas,anyone have info on which are good and fit? thanks AJ :?: :?:

 

[Ratt_Bones]

I'm not exactly understanding the question.
Are you wanting to go 2 stroke, or 4 stroke?

 

[5speed]

thanks for gettin back id prefer 4 stroke but in told all the kits dont fit all bikes i want it fr a dyno duece with the 24 inch tire on the back,we can run engines up to 50 cc b4 its no longer a bike in minnesota

 

[medel]

I am fairly new to motored bicycles, but I think the easiest kit that allows you to run a 4 stroke engine is a friction drive setup. The majority of bicycle engine kits that are inside the frame are 2 strokes. Friction drive kits are often mounted over the back wheel.

 

[Ratt_Bones]

Friction drive (no offense) are horrible!
Not to mention, are illegal almost everywhere.
Mostly though, they are hard on the bike, tires, and wheel itself.

The 4 stroke engines are more powerful, and don't require you to mix your own gas, but are a lot more involved as far as maintenance, and bike set up go. Plus, I personally don't like the pull starts. I hate the look of a lawn mower engine attached to a bicycle.

On the 2 stroke side of things, there are far more aftermarket parts available, and knowledgeable folk out there to help you out in your ventures. The maintenance is far less, and mounting is much easier. Personally, I think they also look much better.

The 4 stroke kits also require a specific bottom bracket spindle/crank that will come with the kit, and is only available with another kit. The kit's are only available in a 48cc, and start around $389.99

The 2 stroke kits are ALL 66cc. Most claim to be 80cc, but actually run 66cc. It matters not what brand engine you get, they all come from the same place/manufacturer in China. There is one exception to this rule though, and only one. That is the Skyhawk GT5 66cc. It has a bigger piston, and longer connecting rod. The only aftermarket part that is tough to find is a performance head. You can get those from Arrow Racing. This is my engine of choice. I replaced the stock 48-T sprocket with a 36-T, and have a cruising speed of 43mph. I'm sure I can get a LOT more out of it with a good expansion chamber, bigger carb, etc.

The standard 2 stroke engines with the same gearing top out around 28mph. Not bad for a $30.00 difference on the initial purchase.

Hope this helps.

 

[barnbikes]

I recently acquired a late 30's Johnson outboard engine I am trying to put in a bike frame. It is a 4.2hp twin cylinder and will probably not be legal here in MN.

Biggest hurdles for me are fitting engine, 90 degree gear box, water pump and a small radiator into a bike frame.

Jon

 

[Ratt_Bones]

I recently acquired a late 30's Johnson outboard engine I am trying to put in a bike frame. It is a 4.2hp twin cylinder and will probably not be legal here in MN.

Biggest hurdles for me are fitting engine, 90 degree gear box, water pump and a small radiator into a bike frame.

Jon

Absolutely not legal on the roadways there, but sounds killer to say the least!

http://www.dmv.org/mn-minnesota/other-types.php

This link should help.