Yamaha Engine vibration

[Wayne]

I have recently purchased a used 2003 19'Polar w/115 Yamaha 4 stroke. It seems to run fine with the exception of excessive vibration at idle speed. Inspection of the aluminum prop doesn't reveal any obvious major damage. The prop paint is scuffed abit and the aluminum is scratched up some on the tips. No obvious wobble in the shaft when I spin the prop in neutral. The engine appears to be securely mounted. Any thoughts?

[Wayne]

Addendum to prior post; I have since taken the prop off to inspect alittle closer. One of the blades is ever so slightly bent. Prior to taking the prop off I checked the max rpm's... It only got to 4800 rpm which is 1000-1200 less than the rated max according to the manuel. Could this minor discrepancy with the prop be dragging the power down this much?? Is the prop the likely candidate for the vibration issue?

[Bay Catt]

A bent prop will deffinatly cause vibration, even if it is only slightly bent. Befor you purchase another prop check to see what the correct pitch is for your motor. Over proping will cause a decrease in rpm,s and also make the motor work harder thus cause greater wear on internal parts.

[Wayne]

Thanks for the tip. I purchased the boat from Homosassa which is notorious for it's rocky shallows. The current prop may have been a cheap replacement to the original.

[jb123]

lowER rpms and vibration...you should do a comp check for peace of mind.