Lose power after 2000 rpms

[Richard Santoyo]

I just bought my first boat. A

I just bought my first boat. A 1987 Christ Craft with a 5.0 omc stern drive. The seller said that the boat had been sitting for almost 2 years. So I took it to the shop and had the carb rebuilt and the fluids changed. Also the thermostat and the impeller was replaced. I took it out on the lake for the first time. It ran good until i got up to 2500 rpms. It started to lose power and wants to stall until I brought it back down to 2000 rpms. Runs good at 2000 rpms. I took it back to the mechanic and he said he found something stuck in the carb and cleard it and ran the boat in the tank and it was fine. I took it back to the lake and it happened again. What should I do next?

 

[sqr1pat]

"omc power steering pump, anyb

"omc power steering pump, anybody know where I might find one. looks like a GM but I can't match it up 1985 5.7L. Need pulley, bracket and pump"

 

[boatin_bob]

"Richard...I assume you are ru

"Richard...I assume you are running new gas in the tank now? Could be many things, faulty fuel pump (not able to pump enough to meet the higher RPM demand), carb problem, float level not set right, sticky anti-syphon valve at the gas tank. Partially plugged gas tank vent. This last one is an easy test (won't cost you anything either) next time your out and the problem happens, undo or loosen off the gas tank filler cap. if the vent is plugged you'll notice a difference right away. What happens is the vent gets plugged with little creatures (spiders, bugs) if enough air can't get into the tank to replace the fuel you end with a vacuum affect that is too hard for the fuel pump to overcome and you basically starve the engine for fuel."