Chris, It sounds like the pitch of your prop may be too high. Several of us on the list have been told by "experts" that X" of pitch was the correct amount for our engine / gear reduction / boat, only to get excessive vibration and not be able to reach anything close to maximum RPM even in a full throttle test. I believe all of us have significantly reduced if not eliminated the vibration by stepping down the pitch &/or diameter of the prop.
Possibly a way to test if the vibration is actually coming from the rudder is to have someone go below and feel the rudder shaft when under power. Would think you would be able to feel something if the vibration is that bad. >From what I have read, if you went to a 3 blade from a 2 blade the prop should be considerably smoother. Brian -----Original Message----- From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Chris Tirtirau via CnC-List Sent: Tuesday, August 02, 2016 8:30 PM To: cnc-list@cnc-list.com Cc: Chris Tirtirau <christian_tirti...@yahoo.com> Subject: Stus-List Bad Vibes from Maxprop? I got a strange vibration/sound coming from outside the hull, under the cockpit floor, when motoring in my 37. After seeing two separate mechanics I was told it was the rudder vibrating and creating harmonics as the water pushed by the Maxprop flows by it. Apparently harmless but annoying and to me unsettling nevertheless. I cannot reach cruising speed with that sound and vibration under my feet. Any ideas? I have the original 2-bladed prop. Should I revert to original, or can anything be done about the Maxprop? I talked to the Maxprop people and I had the pitch set according to their specs but it looks like the C&C rudder design doesn't like it. Christian Tirtirau, C&C 37 Northern Light _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated! _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
