150 Yamaha 2002 wont rev

[Eleve]

I have a 150 hp Yamaha saltwater series That has 330 hours, it starts, idols and get the boat on the plane without any issues, however, when applied full throttle, the motor will not rev past 4200 rpm. The prop is the original prop that came with the motor And I’ve just changed all the cabling which has not fix the problem. It is odd because the motor performs perfectly well until he hits that rpm, and the last 2 to 3 cm of the throttle lever does not change the rpm. I would describe it as if it had a rev limiter. Any assistance would be appreciated on where I should be looking as I’m quite baffled.

 

[mike_i]

Is this a new issue? Did you change anything on your boat lately? Do you know how fast the boat is going when it limits out?

 

[99yam40]

has this boat and motor with that prop or a different prop ever ran higher RPM before in the past?

 

[Eleve]

Is this a new issue? Did you change anything on your boat lately? Do you know how fast the boat is going when it limits out?

I have had the boat for 1 month only, and when I spoke to the previous owner, he said it would rev to 5500 easily, the boat has sat in the shed for 18 months prior to me taking ownership.

 

[Eleve]

has this boat and motor with that prop or a different prop ever ran higher RPM before in the past?

Yes, the previous owner has said that he had it rev to just over 5500rpm

 

[99yam40]

Yes, the previous owner has said that he had it rev to just over 5500rpm

with that prop?

hard to say what is going on unless you have seen it happen yourself.

if this is a carbed motor, maybe they need cleaning due to a jet being partially plugged causing a cylinder to run lean at high rpm( not good for the cylinder/motor.

If it is an injected motor, then maybe an injector/ screen has a problem