New Spitfire prop vibration.

[Dave-R]

Hello All: I have a 2007 Bennington 2075 pontoon boat with a 90 hp. Yamaha. The original prop was a 14 X 11" prop that at WOT I would go right to 6200 rpm at about 21mph. I thought I could pick up a little top end speed with a New Spitfire 13.8 X 13" pitch prop. Tried it out today and it did improve top end to 23 mph, and rpms's dropped to about 5600 at WOT.
The problem is a vibration that shakes the boat between idle and 1000 rpms. The prop shaft is good, the motor only has 90 hrs, with no hits. I have had a lot of boats but never one that vibrated like this at idle. Any suggestions ? Thanks Dave-R

 

[steelespike]

Re: New Spitfire prop vibration.

If you got the vibration with the prop change it's probably time to exchange it for another.

 

[jestor68]

Re: New Spitfire prop vibration.

Perhaps you might order a Solas Rubex hub kit that won't chatter.

Mercury's flo torq hubs are known to chatter at low speed because the hub does not fit tightly within the prop. There's actually a little play in it. When installed the free play can allow the prop to slide back and forth on the shaft up to 1/8", and rotate up to 10 degrees on the prop shaft.

Solas's Rubex hub torques tightly in place, resulting in no free play to cause chatter or vibration. They are interchangeable with Mercury's props using Flo Torq hubs.

The Solas Rubex hub to fit your motor is the RBX 108. You can install it into the Mercury prop to eliminate that free play.