BrecklandLogs
New Member
Hi, any help appreciated - have bought a ported 660 clone and the guy who did it has lowered the exhaust port to the point that it opens when the piston is at tdc by nearly an eight of an inch (see pic). Not challenged him yet, as not sure of all the implications but surely this is going to let charge out or exhaust back in. Seems it is called free porting but not been able to read much up about it yet. Will it be fine or should I ask him for new cylinder?