Yamaha 40 hp 1995

[nomad1957]

I have a 40 hp 1995 yamaha outboard. When, I put the throttle at top speed the boats does not go. The engine has full power and when i have it out of water the prop turns like it has full power. When, i put the boat in water it will go at 1/3 power and then I hold the throttle down the boat will not go at full power.... Rick

 

[99yam40]

Re: Yamaha 40 hp 1995

when was the last time it ran good?
what have you done to it so far in troubleshooting the problem?

Start with the basics, check compression and spark on all cylinders.
Then work on the fuel system