I stripped the prop hub on my Yamaha K-series stainless prop a couple of weeks ago � I just got it back from the shop here in town with a new hub, and will probably be taking the boat out next weekend (after Labor Day).

My question is � how do I avoid spinning another hub? I�ve been advised to run it in forward, neutral and reverse a bit to seat it properly � does anyone have more specific instructions on that? I did run the heck out of this prop from the first time I put it in the water until it spun; I did not realize I needed to break it in slowly.

Also, I was told that this could happen from not having the prop nut tightened down hard enough. I�ve got one of those McGard prop locks on my boat, so there�s no cotter pin holding it down. The fellow at the shop told me to junk my nylon prop wrench and crank the nut on it down as tight as absolutely possible with a metal socket.

This is a 13X21 prop, pushing a boat that could weigh up to 2300 lbs (boat, 115 HP motor, passengers and a full 52-gallon tank of fuel). I was hitting around 44-45 mph with it at 5400 RPM, with a mostly full tank of gas and two people.

Was I just pushing the prop too hard?

Thanks,
John

I believe that rubber hubs just deteriorate with time. I like the Flo Torques because they are easy to replce if you do have a problem. I spun 2 of the rubber hubs over a period of about 20 years before I went to the Flor Torques.

From what I've seen, Most rubber hubs last in the neighbor of 10 years. Some more, some less, some a lot less when you expose it to adverse conditions. I.E. grinding sand in the flats, High tempertures and extreme low temperatures. But for the most part, the reason that you need to break the hub in is to seat the rubber to the cavity that it has been pressed into. You shift from forward to neutral to reverse several times and that makes the rubber conform to the prop. You do not blast off with a new hub, but instead bring the boat to plane at a slower speed. then not over 3/4 throttle for the first 30min or so. You need the prop to come up to temperture before you put it to the max. Also you do not want to surface pierce the prop before you give it time to "set". But I'm sure that Steve has a more techinical explaination than what I have described.....

Hub Seating Procedures.

1) Install propeller, and torque to mfg. Specifications.
2) Operate at an idle, shifting from forward to reverse, several times during first 3 minutes of use. This helps seat the propeller hub!
3) Slowly accelerate onto plane during the first trip to the lake.
4) Re-torque prop nut to mfg. Specifications.
5) Check propeller nut torque periodically.

this is what i recommend to my customers when i re-hub a prop.

your torque should be around 50 ft. lbs. and the mc gard lock is just fine!

Thanks folks -- I appreciate the help.

I got home today and checked out the prop (my wife picked it up for me today). Looks like the prop shop had to apply a good bit of heat to it to replace the hub. The paint on it is blistered around the center, and there's a complete ring of raw metal on the rear, almost like they had to trim it after they put the hub in. The new hub seems to be seated down farther than the old one.

Here's a shot of the prop as it was, after I ordered it. Note how far up the hub extends in the middle:



Here is a closeup of it now, following hub replacement:



And the bubbled paint:



Back:



Does everything look okay with this?

That doesn't look right. Seems like they should not have done that to it. It almost does not evet look like the same prop. Steve is the person to ask.

first off.
a shop should NEVER apply heat to the hub cylinder to replace a hub!
2nd, is that the prop i sold ya? i would have helped ya on the hub problem if so.
3rd..the hub is too far inside the cylinder.
4th.. that shop should have removed the sticker on the hub before installing...lol. that just aint right.

That looks like some amature did it. I have never seen a rehub that looked like that.....I would be ashamed to have done such a poor quality for one of my customers........

I'm a bit worried about putting it on the boat now.

Yeah, Steve ... it is the prop you sold me. Not nearly as nice looking now. .

You made me a generous offer to replace the hub for just the cost of the hub and shipping back to you, and I should have taken you up on it.

I figured the spun hub was my fault, so I went ahead and did it locally, for about $75. Now I'm wondering if the prop is ruined. There's even what looks like a spray of melted brass or bronze inside the prop ... I wonder if they just took a torch to it to melt the old hub out.

call me

I thought that rubber hubs were pressed in.

they are. gotta use the correct funnel, and drivers, and hub lube with a 20 ton press!