For some reason, yes you have an extra shaft and chain run in your setup than what is typically done with that size engine and kart type. The variable clutch (the driver) and pulley (the driven) is designed to give you a good low rpm pull and still make good speed at the top of the rpm range. the gear ratio you're running likely has cut your top speed by at least 5 mph.
I dug back into my old hard drive (literally hanging from cables off the side of my newish computer) to find a pic of a "typical" setup. Of course it's one area that i took very few pictures of. This is a top view, done to show pulley alignment from the engine to the jackshaft. This particular setup in stock form was a 9 tooth sprocket going to about a 60T if i recall correctly. this is a yerf 3203. the driven pulley and small sprocket going to the axle are on the same shaft, mounted on a plate that can be moved for alingment and tension, as can the engine. The driven pulley has one half of it removed for the picture/to fit the ruler.
