How many gears are in the transmission? The XT-225 engine has 6 gears, and the XT200/TW200 engines have 5 gears.
Zongshen obviously modified the cylinder, cylinder head, and exhaust header.
Here are the figures for the Zongshen engine: 72.5mm Bore x 55.7mm Stroke
Here are the figures for the Yamaha engine: 70.0mm Bore x 58.0mm Stroke
Therefore, the connecting rod, cylinder, piston, piston rings, cylinder head, et cetera, are different between these two motorcycles.
Spud
__________________
Spud
"Never argue with an idiot. He will drag you down to his level, and beat you with experience."
Mark Twain
2015 Zongshen ZS250GY-3 (RX3)
2006 Zongshen ZS200GY-2 (Sierra 200)
2005 Honda XR650L
2004 Honda CRF250X
1998 Kawasaki KDX220
Mods made to my Zongshen ZS200GY-2:
http://www.chinariders.net/showthread.php?t=6894