please help

[Alvin douglas]

I resently bought a pair of 200hp efi yamaha 2000 model the first month they ran like a dream, but now I am have problems with the port engine it is not powering up as it should i am only getting 2000rpm when I try to increase power it starts to bucking or shaking but it idile fine but no power.

[boats.net]

If it's in rpm reduction it will be limited to 2000 rpm's, is it overheating or low on oil(check oil level in engine oil tank, should be above bottom line)?Test warning buzzer to see if working properly.