150 Yamaha not running properly

[spring time]

So I tookmy son out this evening to the sandheads and when we were just starting to come in the motor would get to about 3200 rpm and had trouble getting the boat on plane and then it had a vibration in it. But then it would go to wot and no problem cut back the throttle to around 3200 and the vibration would come back it sounded like it was running on three cylinders, any idea so I can try and go out this weekend if not I’ll have to take it into someone thanks

 

[Ringo]

Sounds like a fuel problem. Do you have a Racor filter on the boat? Did you check the filter for signs of water?

 

[spring time]

Yes pulled it and nothing that’s what I suspected

 

[Deejray]

Have you tried pulling the plugs yet?

 

[scott craven]

Sounds like harmonic balancer which was a problem on some of the 150HP Yams.
Check with your dealer