Yamaha 200hp won't go above 2800 rpm

[dandaman58]

Have a 200hp saltwater series, 2 cycle, carbed. I'm guessing the motor is circa 1990's. Data tag is scratched up. Anyway, had the local shop do a lot of maintainence last summer and was running fine. Took it out last week for the first time this year and it started fine. Ran it between 3600 and 4200 rpm for about 20-30 minutes and ran fine. Passed by a fuel dock so I slowed to a no wake speed. Throttled up to about 3200 rpm and a few seconds later it dropped back to 2800 rpm. Gave it full throttle and very briefly got a rise in rpm but settled back to 2800 rpm with lever full forward. Ran smooth, just would not go above 2800 rpm. Got it back to the dock and next day checked fuel/water filter in hull, fuel filter on the engine, primer bulb, fuel vent. Carbs appear to be opening all the way. Filled it with non-ethanol fuel last fall and put in stabilizer. Took it out again and started right up, ran smooth but would not go over 2800 rpms with lever full forward. Any ideas cuz I'm stuck.

 

[lander12]

So you are using last year's fuel? I generally do not trust old fuel (even with stabilizer). Anyway, suggest that you carefully check over the motor for compromised connections, vacuum connections that may now have a small leak (sucking air) which can affect fuel delivery from the fuel pump. Sometimes connection clamps can vibrate loose over time. Also small cracks in rubber hoses that carry vacuum air. The fact that the engine runs smoothly (although lower RPM) is probably a good sign. Replace anything that looks suspicious. Sounds to me that something has come loose.

 

[alice]

have you checked all wires and cylinders? Are there any holes in your fuel pump?

 

[dandaman58]

Thanks for your reply. Will do tomorrow and post results