Shake/Vibration 1800RPM on Volvo 5.7 GXI

[Bill2440]

Have a 2008 Ebbtide 2440, 5.7Gxi Duoprop. Boat has 20 hours, just bought this boat, its like new, but has this shake on takeoff and up into the higher RPMs. The engine is smooth in neutral. I have had the drive removed and checked coupler, joints, bearing, are all like new. Outdrive output shafts appear to run true, both props were checked and found to have run out by a machinist,I was told .030 out. Has anyone heard of this? Waiting on new props,

 

[bruceb58]

Re: Shake/Vibration 1800RPM on Volvo 5.7 GXI

Was alignment checked?

 

[Texasmark]

Re: Shake/Vibration 1800RPM on Volvo 5.7 GXI

What kind of shake? Vibration, mechanical noises, what frequency....high pitch, low pitch, rpm associated? Was any noise associated with it...dry bearing squeal, wobble rumble? Was it with the helm dead ahead or in a turn? If a turn, slight or maxed out. Did the noise increase as a function of the degree of turn?

.030" on a 14-15" dia prop sounds like nebulous to me. Props have no dings one would assume; haven't been on the bottom or hit something with it.....no bent prop shafts.....can you set the skeg on a concrete floor and check for prop shaft alignment, i.e. tips of both props clear the floor with the same dimension over 360 degrees of rotation each....within .030" or thereabouts.

All mounting hardware associated with engine to outdrive to floor stringers to transom are tight......

Mark