you will need a 4-stroke mount designed for that engine, a 4-stroke transmission, a centrifugal clutch, and a new throttle cable (for 4-strokes). and of course you will need 4-stroke oil. buying them separate is almost as much as just buying a new 4-stroke kit.
ALSO, note the 4-stroke engine is bigger on all dimensions than your 2-stroke engine so check to make sure that the engine does fit. even if it does not, you can just buy a cheap used bike with a frame that does fit.
AND, the default centrifugal clutches suck major donkey. i forgot who but an experience 4-stroker recommended the clutch from staton-inc with good anecdotal evidence. to avoid headaches and possible damage to your transmission, I would get that $40-50. it is pricey but the clutches from bikeberry and gasbike are $20-25 and crap and the China pocket bike ones are $5-6 but also crap. LOL
In terms of power, I think they are about the same but I am a light rider but someone said the dyno is more linear for the 4-stroke than the 2-stroke. the staton-inc clutch will also help with the power since it has much more mating surface than the default clutch.
Riding wise, i think 2-strokes are more interesting with the interplay of the manual clutch and helps incase you want to try motorcycles later so you wont be a total noob with the motorcycle clutch. 4-stroke is like a scooter. but with both you should pedal to 8mph+ and then engage the motor.
Price-wise and in terms of learning, I think the 2-stroke is much better. You have to actually know about small motors and have proper tools to get the most life out of your engine. 4-strokes have little maintanence (i change oil every 200-250 miles and thats it) but its like a scooter you just use it to go but you dont really experience and learn as much as a 2-stroke.
