1999 Yamaha 115 hp v4

[Murray10]

Hello, my 1999 115 hp v4 does not seem to want to open up, and if you give it full throttle, will stall. This came on very suddenly and is now sometimes hard to start. Up to now has worked very well. My mechanic has found that the bottom cylinder is not working, getting 130 psi on all four cylinders, tried a new fuel pump, cleaned the carb, switched coils, and all with no positive results. The cylinders all seem to be getting a spark and gas. Possible bottom crank seal leak?

Thanks

[boats.net]

Could be air leak in crankcase or bad reed valve.