DF115 2008 Noise

[Nereus]

Hi

My DF115 has started be noise when it reach above 2000rpm, but only when in gear. I feels like it makes some resonance and makes this loud buzz noise.

I've checked the oil, installed new spark plugs and water separator/fuel filter.

I've got no alarms, and it runs fine besides this loud noise/resonance.

Have anyone got an idea what the problem can be?

[Harper]

Haven't run aground, or hit anything with the prop lately?

[WEDOCQ]

This might sound funny, but have you checked the muffler? Seriously tho, there is a small plastic "muffler" on the small exhaust port next to the pee-stream. Apparently its common (and fairly easy) for those to pop out. When they do, the motor runs fine, but sounds more "resonate" like you described! Super cheap to replace on this site...
-Shawn

[Nereus]

Thanks for your replies. I havent hit ground. And the muffler is there. I've tried to lose that last year. And its a different noise this time.