So I ported my 48cc BBR engine and I did not noticed much power increase. I was wondering if I have to modify the exhaust and intake because there’s not enough air flow? This is what I did to my cylinder. This is not my cylinder I didn’t take a picture of it but that’s what I did to the transfer ports and I opened up the exhaust port and raised the exhaust port a little also opened up the intake port. Dose anyone know if the carb. And intake and muffler are the same as the 80cc BBR motor? because then I would think that it should have enough air flow to feed a modified 48cc engine if the same intake, carb., exhaust feeds the 66cc engine.