50 hp 4 stroke troubles

[hert86]

Having trouble with a 2000 50 hp 4 stroke. Starts and fast idles great. When you place it under a load it acts starved for gas. Can't get the boat on plane. I have cleaned the carbs, checked the plug wires, changed the plugs, checked the fuel filter, and am using new gas. Any suggestions?

[boats.net]

That would be hard to say it could fire, fuel or compression.

[Ken]

hert,
Is it missing when you try to get on plane, or running smooth but just no power?
I would suspect fuel pump or timing on the ignition - might want to get yourself a Yamaha shop manual and run some tests.
Good luck,
Ken K