I recently traded a 2012 Yamaha (carb engine) for a 2014 Yamaha Drive (EFI engine). The 2014 has an 8 to 1 rear gear set, 23 inch tires and the final drive pulley is from the 2012 (it is slightly smaller in diameter when compared to the 2014 Drive). The cart presently has a top speed of 28 to 30 mph. The tach is displaying around 750 rpm on top end. The Yamaha mechanic said to double the rpm reading because the 2014 engine fires every other cycle, and not every cycle like the 2012, which would tach around 2200 to 2300 rpm and also travel around 28 to 30 mph. The 2012 also had the 8 to 1 gear. The Yamaha mechanic could not "turn up" the 2014 due to some type of rpm limiter. Can anyone verify the firing cycle and also let me know how to defeat/bypass the speed limitier. Thanks.

I own a Yamaha BWS 50 scooter (2 stroke). It runs great but recently, the engine will "bog down" when going up a long hill at full throttle. Naturally, with a 50 cc engine, the scooter engine will slow down going up hills, but this is different. The engine suddenly lacks power, almost like it is running out of fuel. When this happens, I release the throttle once or twice and its fine after that. There is no fuel filter on this bike. It never happens on a straight road, even a full throttle. This is not a transmission problem, it's definitely the engine lacking power for whatever reason. Could the carb become flooded when going up a long hill at full throttle ?