Bored bings unless done perfect. Sized perfect ( 14 mm 15mm ect.) not goofy between sizes (5.4mm 14.7 mm ect.) and use correct atomizer for size (#222-217 for 14 mm #217-215 for 15mm) are hard to jet, don't idle good and just don't run good through the range. See if your choke is locked on the lever correctly if not it will open when throttle is opened and close when throttle is closed killing the engine. I run 72 jet with 222 atomizer on #2 open port 2 hp topend. Every # 4 puch cylinder I had was a slow 1 hp with a restricted intake exhaust port. Your not going to go anywhere with that topend get a 2hp one