There's a lot you can do to pep up that engine. I have the performance exhaust and cam from AGK, of course they have been out of the cam for a while. Sucks. I also drilled out my main jet to match the increased flow of air. AGK also has a nice bored out carb for the 49cc. Gearing change can also improve performance. If you're running too small a rear sprocket your takeoff and hill climbing can be affected, I had a 36t, but upgraded to a 44t and may go up to a 56t in the future. Also Staton Inc. has a super duty clutch that engages at 3000rpm instead of the stock 2000, that gives the engine time to build up power before it is applied to the gearbox. A much better takeoff than stock. If you're looking for speed, then go with a smaller pulley in you G4 and that'll increase your top end. Any of these things can be done cheaply without having to re-engineer your bike for a new engine.
mincraft dont listen to this guy below you here tad..... that cam is a waste of money.. you will have problems.... an agk plug is just a better plug because its not from china it dosent give you more power...
the clutch dosent give you more power..
dont drill out your jet if you mess up it will not run.. those jets are designed to be at a certain size to run right.. if you want a bigger jet order one..
all this stuff wont help these motors you might get .5 hp out of it not noticeable.. you want power and tourq then you buy an old 5 hp motor off a lawn edger and get a cvt gear it right and there you go..
those 99 cc and 98 cc are junk from china they aren't bullet proof like an older motor before all this Chinese junk hit the market..
you will be just wasting your money putting all this stuff on... if you want more power get a Moroni motor or a 125 cc engine out of a pit bike there is fab work also you can get real moped motors.. they are cheaper..
the way you get more power is with stroke, bore... and stroke of the piston.. then comes more fuel and exhaust.. those old motors have high torq and you can beat them into the ground and they will still work these new ones you over rev and you blow a rod 3500 rpm max..
no disrespect tad ive just had a long time to work on these bikes and the 2 stroke and these husangs are junk over priced kits and crappy workmanship on them...
how do i know all this stuff.. common sense working with them and im a ase master certified mechanic..... not to toot my horn lol