You can bore out the exhaust which will give you a little more accerleration. you can also put in a bigger jet in the carb, but be careful with this one cause it sometimes doesnt work
Chalky White
July 2009
I don't think these small four strokes can, without a great deal of work and expense.....the restrictions come in the form of carburettor size, camshaft profile and exhaust port size so its probably better to trade up to a larger capacity machine when you can.