Yes your right there to port a two stroke engine you realy have to know how to jet one..With the work Ive done on this one id say stock jetting will be fine but if not i will mod the main jet for more fuel..if you where to port one in a bigger way and not tune it with jetting it would be seized in no time...The biggest restriction on a mower that ive seen is the air box they let stuff all air in and I think its more a safty thing to stop it from ever running away with hi revs,and also a big restriction is in the fuel system the carb can only get what the pin hole of a feed will let it, also a safty thing id say to stop it ever getting a little to rev happy and running away...With this mower i hope to have picked some torque up not looking for more revs..Cheers
