(1) The cover needs shimming because the crank isn't cut for a ZX trans and the electric start gear needs to be changed to a ZX one or add a washer to the back of the starter gear to move it out because you'll have a lot of play since the cover will be move out. The nut sticks out once again because the crank isn't cut for a ZX trans. Most, if not all aftermarket cranks are made for a ZX trans and will solve most of these issues.HOPE THIS WRITE-UP HELPS AND MAYBE SOME OTHERS CAN PUT IN THEIR 2 CENTS. (1)BY THE WAY, COVER WILL NEED SHIMMED TO CLEAR OR GET THICKER GASKET FROM ONE OF THE MODELS LISTED. I DO NOT KNOW IF THIS SWAP RENDERS THE STARTER INOP SINCE THE DRIVE PULLEY IS FURTHER AWAY FROM STOCK LOCATION, I DO KNOW THE KICKER WILL WORK. THE ZX DRIVE BOSS IS 1/8th INCH LONGER AND YOU WILL END UP WITH 1/4 INCH WORTH OF SPLINES ON THE CRANK.
EDIT 12/4/09 (2)If using Sym dd50 pulleys it is recommended to add 4-6 spot welds to reinforce weld, i had 8 spot welds done today. I think the Kymco pulleys have a good weld and shouldn't need reinforced. So...even if rear pulleys are Chinese you can remedy that!
(2) I never had to weld any of my rear drives, most rear drives break because of a to stiff center/compression spring, this is a problem that isn't happening as much now days as it used to because people finally learned running super stiff center springs aren't good for your trans. Also, the welded rear pulleys still break.
) Glue the washers to the cover or the crankcase and you won't have to fiddle so much with them every time you swap rollers. Have a look inside the front Honda cover for possible belt foul issues, just in case. I strongly recommend you leave the rear half-cover off.
!!) my statement was "... the Kymco pulley will require less (maybe NO?) shimmage. It's in there if you care to look it up. Stick a flat washer behind your Bendix gear too, and then check that the teeth engage fully when the Bendix throws out its gear. It needs less than a mm thick to engage on mine.