I have I 94 yamaha yzf 750 and I just replaced all the guts of the engine. I got it running and after about 150 miles it stopped running so I took the spark plugs out and they were full of carbon. So I cleaned them but obviously it is running to rich. I took it in and got the carbs synchronized, the water pump seal changed and somehow it ran perfect for another 50 miles. Then aside from me running out of gas when I ride it it bogs down. On a cold start it won't do it right away. But once the bike warms up it starts bogging again to the point where I can barely accelerate at all without it bogging down and dying. It also pops out the exhaust and seems to be getting worse. 1 other thing I can think of which confuses me even more is the idle speed was perfect until today even after it bogged and died on me it was fine. But today the throttle was like it was sticking but it isn't I'm pretty sure. When icome to a stop and hold the clutch the rpms will go down to about 1000 but then it will jump up to 2 or 3thousand which obviously isn't right. I'm completely stumped and 2 mechanics I've taken it to obviously don't know what it is so I'm looking for any help or ideas I can get PLEASE