2008 Yammy 150 4 stroke.

[Karma-Kazi]

Hey guys. Question for some of you knowledgeable fellows.

I was out in a boat with a 2008 Yammy 150 4 stroke and as I was powering up and reached 4600 rpm it began to have a high pitch vibration/humm. As I increased the speed to about 5200 rpm's It went away. The start and stop of the sound was sharp. It dident build up and slow down. It was there and gone. I did it every time at those rpm's. Its on a 20' double eagle with and aluminum pod.

Anybody ever have somthing similar happen?

People have suggested the prop but it looks brandnew with no dings or anything.

-Steve

 

[profisher]

I'm thinking cavitation. Try getting to the 4600 and keep it there so the vibration stays...then try trimming the engine down to see if it goes away without changing engine rpms.

 

[Clipper]

You might be getting a harmonic vibration at those specific rpm's. Something is vibrating in sync with the engine and causing the noise. Maybe check to make sure everything is tight under the cowl.

 

[Karma-Kazi]

Thanks for the replies guys, I belive it to be the harmonic balancer. It is somthing that was nearly a recal in those motors and have been a problem in the year of motor 2500$ fix yowza... Guess it could be worse whole engine could be fried.

-Steve

 

[Battle Bay]

check with a good yamaha dealer, if the engine has under 1000hrs on them then yamaha will fix it.