Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Prop Question

Posted by Beso21 on 08/11/14 - 5:44 PM
#1

Just purchased new ETEC 90 2 stroke that is on 1966 16' Custom. Not sure of the prop pitch but first time out had some vibration around 1500 RPM. The new motor is replacing a 1986 VRO 90 HP and there is so much power difference that I am wondering is this the cause of the vibration. I assume that the Etec 90 come with a standard pitch prop. Like mentioned earlier had boat out for quick 1 hour test and besides the vibration at low RPM it ran great. Advice needed please. Is this a prop issue?

Posted by Joe Kriz on 08/11/14 - 5:46 PM
#2

Motors don't come with props.

What prop did the dealer put on your motor?
What brand, size and pitch?

Edited by Joe Kriz on 08/11/14 - 5:50 PM

Posted by Phil T on 08/12/14 - 6:43 AM
#3

Where is the vibration coming from? A railing?


Posted by tedious on 08/12/14 - 9:35 AM
#4

If it's running smoothly at other speeds (and it sounds like it is) then what you have is a resonance - something is ringing like a bell because its natural frequency is the same as one the motor is producing. Find what it is that's vibrating, and tighten it, loosen it, or damp it somehow.

Tim

Posted by Beso21 on 08/13/14 - 6:37 PM
#5

I feel the vibration all over at the low RPM range(around 1500) as mentioned. Inside of boat was redone this summer and I have checked all possible parts having to do with the re-rigging, console etc. Everthing seems to check out. The new prop is a SS Viper but not sure of size and pitch. Motor is rigged to the #3 hole. Is there a standard size for this 1966 17' Nauset. boat is used 95% of time for fishing bays around Galveston