4 strokes:
Pros:
more power (of course 2 times displacement or close to)
more torque
improving constantly
less rebuilding
no mixing gas
less pollution
easily converted
Cons:
more expensive
heavier (bigger engine)
more moving parts, therefore IF something goes wrong, will most likely screw up more than one thing
not same thrill (IMO) as two stroke
PRO+/-CON:engine braking....con in my book
sound
smell
2 strokes:
Pros:
lighter weight
kick ( :) )
less parts
more power for half (close to) displacement
thrill
sound
smell
cheaper exhausts
Cons:
pollution
rebuild often
class will smoke you most likely
not as easily converted from mx to trail
mix gas
PRO+/-CON: won't be around much longer
I'm sure I forgot a lot, but this should help. Anything that is a pro for one, should be a con for another and reversed...ex. pro:twostroke:lighter...con:fourstroke:heavier