New Prop now I have a Vibration!!!

[spiphen]

I have a 1999 VP 4.3GL 190hp with sx sterndrive. I replaced my old prop with a new one with same pitch but it is a different brand (Hustler). AT WOT or just under, I am now getting a slight vibration. The new prop seems to have a little more cup to it. Could the cup in the prop be causing the vibration or is it something else? Thanks in advance for your thoughts.

 

[spiphen]

Re: New Prop now I have a Vibration!!!

Sorry guys if bumbing a thread is illegal here. I'm just looking for some direction on this topic. Thanks

 

[Texasmark]

Re: New Prop now I have a Vibration!!!

You'd think that the Hustler alum prop would be pretty concentric, uniform or whatever since it came from an investment casting....I have one. But you might remove it and inspect your installation and the replaceable hub to insure that it is installed correctly and that it is manufactured correctly....brass hub centered in plastic, no deformities.

A way to check this could be to measure the tip distance of each blade with a measuring device to the ground while the boat is on the trailer and the outdrive is sitting vertical. The more accurate your instrument the better. This would/could tell you if the prop rotation is eccentric. If so, troubleshoot till you find the cause.

Also the local merc dealer uses 90 ft-lbs of torque on the prop nut and guys on here use 100. The high torque is required (I'm told) to get the hub properly mounted to the thrust washer that preceeds the prop on the propshaft.

HTH

Mark

 

[Tail_Gunner]

Re: New Prop now I have a Vibration!!!

Is this a vibration or low frequency grumle (aka does your hull seem to vibrate), also does it matter if your motor is trimmed in or out, or does that matter at all??