I recently found out that T50 fourstroke has restrictor plate in air intake. I removed it and gained about 250 more rpm. The T60 fourstoke doesn't have the restrictor plate in the intake. I would assume the F50 might be the same. It is not hard to remove it Take the Baffle off the front of the intake the little plate is right there in the baffle, take it out put the baffle back on and try it out. More air is allowed to go in freely the ECU adjust for that So you get a little gain in HP.