here is some info to help you out..
if you go to ebay and enter this number into the search field:392863049895
it will bring up an auction for what you are looking for.
has everything needed to do a 4 stroke bike conversion
1x 49cc 4 stroke engine
1x Gas tank,Plastic gasoline fuel line,fuel value
1x Adjustable chain idler
1x 44 tooth 9 hole sprocket
1x Chain guard
1x Extra wide crank/sprocket
1x Fiber sprocket mounting rings,9 sprocket bolts,3 metal retaining segments
1x Engine Mounting plate with universal mounting brackets
1x Spark Plug Wrench
1x Misc.mounting bolts with nuts
1x Heavy duty #415 chain
1x Twist grip throttle with built-in kill switch
1x Adjustable throttle cable
this comes with the wide crank set as well as the transmission we taked about.
the engine is the 142F engine. same one i run on mine.
Ideal for bikes with 26 inch frames and similar
the guy is offering all of this for $182.00 or best offer.
and hes only charging $12.00 for shipping.
i keep track of these auctions because im looking to do another conversion soon.
plus this guy isnt like the others where he is charging bookoo bucks for shipping.
this is everything you need except the bicycle to convert. that makes it easier than trying to find all the different parts.