Prop Spin Question

[mikeherb]

I was out with the family today and my outboard started misbehaving. I normally run 5400 RPM at WOT which is right at the 5500 max for my outboard. I run 21-22 MPH as well.

Today I was pulling my son and another 7 year old (no more than 110 lbs between them) on a tube and my outboard shot to 6100 RPMs and would only run 17 MPH. I have heard folks talk about prop slip or spinning a prop.....do you think this might be that? How can I tell for sure? WTF is spinning a prop anyway? Have I stripped the splines on the hub maybe?

I don't remember hitting anything and there is no damage on the prop and the boat ran perfect yesterday.

Any thoughts are greatly appreciated.

[HandymanHerb]

The prop has rubber to stop the shock from the engine so you may have metal on the inside and outside but there seprated by rubber and that's what spins and doesn't tranfer all the power to the prop, time to head to the prop shop

[lakerunner]

My 90 doesn't have the rubber hub as older props did. It has a hard plastic like cone the fits inside the prop and over the splines. Pull your prop and see if you have the same type. If rubber you can see where the rubber is torn and wrinkled between the spline and prop hub. Sure sounds like what happened

[mikeherb]

I'll pull her out today and check it out. If it's just the prop I can sure live with that.

Couple more questions though:

If it's spun can a prop shop repair that? I would assume the hub can be rebuilt.

Secondly, anybody know of a good place to ship a prop? We don't have any place within 100 miles of Summersville that would fix a prop.

Thanks again for the help.

[lakerunner]

Any marinas or dealers near? that's where to start.

If rubber they press out old and press in new, if cone just get a new cone

[Richard_Kuhn]

I spun the prop on my "81" Merc 90 HP 2 weeks ago. I was at about 3/4 throttle, 30 mph. The boat slowed down but the rpm stayed up. Once I throttled down I was able to cruise about 8 to 10 mph and get back to the ramp. I got a new prop and hub from iboats.com. Put the prop on last week end and ran the boat again. All was good!! I could not see any particular defects in either the rubber hub or the prop. I am going to order a new hub though and have a complete spare prop if needed. Hope this helps.

[leon phelps]

I always buy a new one, and get the old one re-hubbed during the winter. In the winter, most prop shops have a good discount on the fill work that does not need to be completed until the start of next season. I win and they win.

Then I wind up with a spare on board. I will eventually sell the spun prop on ebay or craigslist to knock off a few bucks from the cost of a brand new prop. Hey $20 is $20. This way I keep newer props and get a spare.

Good luck.

[mikeherb]

I sent a message to Dan's discount props in TN to get an estimate about getting the prop fixed. The guy was real nice and straight forward but he has me a little baffled. He said it is highly unlikely the hub is spun and that the prop needs re-cupped. I know pontoon props are double and triple cupped but has anyone heard of having to re-cup a prop?

Based on folks on this site it's not uncommon to spin a hub. The more I look into this the more confused its becoming.

[HandymanHerb]

Forget that guy right off the boot, does he think it just lost pitch running too?

[lakerunner]

I have been boating for 35 years and have only spun a hub 2 times. I also have props cupped for more bite. It was cheaper than a new prop

[mikeherb]

So here is the final outcome for this thread. There is nothing wrong with the prop at all.

I pulled my boat out last Thursday to haul it up to Ohio. As I was checking my tiedowns I found a 2 foot long stick about 1 inch in diameter jammed into my engine pod. It was causing the prop to blowout apparently.

I put the original 15 pitch back on my boat and it runs perfect with the new center toon.

Thanks for all the feedback though...learned a lot about spinning prop hubs.