I have a 2011 Yamaha 175 VMAX. Motor sounds like it is bogging down when I try to get on plane. Eventually it will "fire up" and I can get on plane. Once on plane it will go back to slowing down then speeding up. Back and forth the whole time. Very intermittent. RPMs are 3000 when trying to get on plane. Once one plane it will vary between 4000 and 4500. Top speed is 49 when it used to be 55-58 depending on the livewells being full. Even when I'm idling I can feel the change in speeds like the motor isn't consistently firing. No knocking and the motor cranks up fine. I first thought it was bad gas but ran the old tank out and put fresh gas in and ran it down to 1/4 with the same problem. Any thoughts? Spark plugs or wires? Fuel pump? Thanks

sounds like high psi pump bad or filter on bottom dirty

we can check it out for you pm with question

Boat shop says there is debris in the fuel. They have to send off the fuel pump and filters to be cleaned. Is it normal not to do this in house and send them off to be cleaned? Also, not sure where the debris came from. Fuel lines/tank deteriorating?

You didn't say how old the boat is, but you need a water separator/fuel filter between the fuel tank and the motor. That should stop the debris from the tank but you need to change it at least annually, more often if you suspect a problem or log a lot of hours.

Also, there are a number of filters inside the cowling on the motor that need to be changed regularly.

Wayne