Just starting

[adsimi3]

I am just getting the bug to build a Motorized bike. Looking for some help on the best engine kits to buy and some of the pit falls to stay out of. Would appreciate any help. Dave

 

[GearNut]

I am not going to let that genie out of the bottle. I know I couldn't get it to go back in!
Here are a bunch of threads related to your question:

http://motorbicycling.com/f37/first-time-whats-best-engine-33861.html
http://motorbicycling.com/f3/best-brand-80cc-bicycle-engine-34306.html
http://motorbicycling.com/f4/how-long-can-you-ride-2-a-33568.html
http://motorbicycling.com/f4/about-how-many-miles-does-your-33444.html
http://motorbicycling.com/f37/hf-98cc-predator-nice-alternative-99cc-32197.html
http://motorbicycling.com/f37/friction-drive-vs-chain-one-better-29984.html
http://motorbicycling.com/f37/school-me-transmissions-32361.html
http://motorbicycling.com/f37/best-4-stroke-engine-31896.html

And finally a thread that deals with alot of things in general but also contains the things that you need to look out for concerning the bicycle that will be holding everything together.
Classic Instructions for Building and Repairing Motorized Bicycle Engine Kits - Motorized Bicycle: Engine Kit Forum

 

[leadfarmer]

The main thinhs I wish I would have appreciated on my recent first build are: large diameter frame tubes require an adapter plate be fabricated and a coaster brake requires enlarging the sprocket hole and bending the Bendix arm.
So, if you want a fast build, get an older(small tubing),non bendix arm bike.
In general, be ready to come up with solutions to your engineering difficulties, and you will solve them in a day or two.

 

[inked1974]

welcome to our family! take gears's advice and read up as much as possible. the ultimate choice is yours. we have many opinions of what is "best" here. we have unlimited information on all related topics. ask yourself what you are looking for and get it goin!

 

[MotorBicycleRacing]

I am just getting the bug to build a Motorized bike. Looking for some help on the best engine kits to buy and some of the pit falls to stay out of. Would appreciate any help. Dave

You are in Simi Valley so you are in luck because PistonBikes.com
has a store front right there.
It's kind of hard to buy kits now but they still have some left if you
get over there fast.

Rob and Gregg from Piston Bikes are going to be at the SoCal Race
at Grange Motor Circuit on Sat Oct 22nd which is in only 5 days.

Hope to see you there.