yes I'm a newbie to this site and even more importantly to jetski repair. My son just purchased an 88 Kawasaki 550. It has been bored out and I think has a larger mikuni carb on it. The base opening measures about 45mm. My problem is we just rebuilt the motor, new crank seals..the shop said everything looked good. There are three ports for fuel/pulse lines on the carb. I would guess that the big round piece on the side of the carb is basically a pulse activated pump, correct? I read somewhere else on here that the crank case pulse line goes to the center barb on the round device(lower part) the inlet is on the end of the round piece and the return line is towards the back(left) of the carb basically near the carb throttle body. The motor will only run if you pour gas directly down the carb. I have tried switching lines, took a large cc syringe and pulled fuel into the plastic bulb-like container(looks like a water separator). If I crank the motor over if after trying to put fuel into either the return or inlet, it just spits it back out. I took the pump apparatus apart and can't really see anything obviously wrong with any of the diaphragms. Shouldn't I be able to feel suction if i put my finger over the inlet, having the pulse line attached? I really sick of trying to figure this out and even more sick of how much $$$ i already have into the relic. I know my way around cars but 2-strokes are a different animal..baically, it acts like it isn't pumping fuel into the motor...any help would be appreciated.