Propeller Hubs

[Cat Tales]

My new (2006) Yamaha 9.9's have about 300 hours on them and I just replaced both propellers after the rubber hubs disintegrated. I carry two extra props on board for this reason, and they are the 2nd set I've replaced in 600-700 engine hours. The re-hubbing shop I take them to mentioned that this is a common problem with the high-thrust 9.9's because they deliver torque similar to a 25hp engine and Yamaha has not designed a more robust hub to compensate. Those engines have three different prop choices: all 3-blade & 11 3/4 diameter, with a choice of either 9-1/4", 11" or 12-1/4" pitch.

1.) Have everyone elses experiences been consistent with these engine hour/prop changes?

2.) We generally motor at 50%-75% power, between 6 and 7 knots, depending on current/wind. As a side note - All failures accured when motoring into a strong headwind (20-30 knots) and current - No manuvering room to raise sails & bear off. Does anyone think that any of the specific pitch sizes mentioned above would have a lesser or greater chance of hub disintegration?


Thanks,
Chris

[Tanah-Keeta]

On Tanah-Keeta (36089) my old engines had 1600 hours with the same props.. no hub failures and my new engines had around 5-600 hours.... don't remember exactly... with no failures. I always ran at 4000 rpm.... about 6.5 kts. In our many trips on the ICW, we had ample opportunity to experience wind and current on the nose with speeds down to 2-3 kts.... and sometimes racing to a bridge at 4500 rpm. This is one reason I have a 34 powercat now.

[36041]

Chris,

Our 1999 Yamaha's ran for 800 hours before we ended up spinning both props within two weeks of each other. We switched to Piranha props after that and went on to put an additional 1700 hours on the engines without issue. We liked them so much that we ordered another set for our 2 new 2007 Yamaha's that we just put in.

Just my two cents worth.

Tom
36041
www.tendervittles.net

[Cat Tales]

Tom,

Just went on the Piranha site and could not find props available for our newer model engines. Do you have the part number for the props you ordered?

[thinwater]

http://www.soderbloom.com/proprepair.html

It took 2 weeks, round trip, and now I have 2 good spares.