Yep, the 200 AC is only 12-13HP, only 20% more than the 125cc. But the TORQUE is MUCH higher, and with peak power at only 6750rpm standard, the engine would last forever. The Malossi 190 kit by itself, no other changes and everything else stock, would only make slightly more power than this, mainly due to the lighter piston, better heat transfer of the alloy cylinder, and reduced blowby from performance rings, but probably still only 14-15HP.
If you need more power you need to look at the things that feed the airpump........intake system, exhaust system, and the head. The liquid-cooled Leader 125cc in the Sportcity apparently makes about 10kW compared to the aircooled 7kW, bore and stroke are the same, the extra power coming from better head flow, a few more revs, and more efficiency.
Dyna, I think another way to get a performance head on the Leader may be to check head/cylinder bolt spacings on a few aircooled cylinder/head combinations from other engines, and adapt the whole top end from the barrel up onto the Leader cases, sort of like putting liquid-cooled Rotax top ends on old 2T Vespas. You could even adapt something by making a plate to bolt to the case using recessed bolts, ten putting on studs to hold a complete top end off something else, like XT Yamaha/XR Honda, etc, all you need to check is the timing chain to camshaft sprocket distance is the same (possibly by using sprocket spacers?), and lines up with the bore.
I might be easier to fit bigger seats, thicker but angled bronze valve guides (to move the valves apart more), then cut the chamber and ports to suit the bigger sizes in the standard head.
I spoke to them again about the crank, but I'm still a bit undecided. I'm not worried about the quality of the crankshaft, as it is a OEM Piaggio crank, just modified to fit the Leader case, but I'm trying not to get madly carried away! The whole deal for me was just to get an aircooled scoot that could cruise at 90-100kph, and to achieve this the easiest and simplest way possible, not to have something to suck the mirrors off a GTS300!
I haven't had the cases apart on a scoot before (but have had dozens of inline and Vee 4's apart down to individual bolts, so not worried), but I think changing the crank, although not difficult, may be a lot more involved than just bolting on a big-bore kit and an upgear kit........which is why they are so popular of course! I might even just need to port the head, build and exhaust, set the intake length, then throw rollers at it and the job is done, I just don't have that level of experience with these things.
I do know that for me at least, on an airflow limited motor of any sort, getting more capacity from increasing the stroke can usually give better results than increasing the bore size, in terms of average power across the range. Scoots don't need much power range though, so maybe that isn't an issue for these things?
Oh yeah, and one of these German hotrodders involved with Scooter-Centre has a liquid-cooled, 4V headed 278cc Leader engine running and going.........and putting out 25RWHP on the dyno. 8)