Bought spare prop, but hub looks different

[TomB985]

Hi guys,

Just bought a spare prop for my boat. I was able to get a Merc BlackMax 14.5 x 19p prop that was nearly brand new for $75 off of craigslist. It's not ideal, as my boat has a 23P prop that's performing great, but I figured that this would be a great backup prop should something happen on the water.

But looking at it, where the hub would go looks different than what I have on my boat, as IIRC the factory hub has splines that go into notches in the center of the prop, but this one has no such notches for the splines to go.

So I imagine all I'll need is a different hub kit, can anyone help me select the right one?

Thanks!

 

[Bondo]

Re: Bought spare prop, but hub looks different

Ayuh,.... Yer missing the splined insert....

 

[Dhadley]

Re: Bought spare prop, but hub looks different

That's a square bore prop. All you need is a hub kit for your Merc outdrive. You can get one here or ay West Marine or most any dealer.

 

[TomB985]

Re: Bought spare prop, but hub looks different

Okay, now I think I understand. When I remove the prop that came with the boat the square insert stays with the prop...I always assumed that it was part of it. Guess not, I'll now be looking for the correct hub kit.

Thanks everyone!

 

[ufm82]

Re: Bought spare prop, but hub looks different

You just need the Flo-Torq kit. Not a big deal- maybe $40 or so.

 

[cribber]

Re: Bought spare prop, but hub looks different

Also try tapping off the old hub kit on you shaft with a rubber mallet. I'll bet it's siezed on there so spray some WD-40 on it overnight to help loosen it. Normally there'e enough friction that the hub kits stays attached to the prop. I'll bet the PO never greased the shaft.

 

[TomB985]

Re: Bought spare prop, but hub looks different

Also try tapping off the old hub kit on you shaft with a rubber mallet. I'll bet it's siezed on there so spray some WD-40 on it overnight to help loosen it. Normally there'e enough friction that the hub kits stays attached to the prop. I'll bet the PO never greased the shaft.

Yeah...I'm the original owner, the boat is only 5 months old! When I remove the prop the metal insert comes right out, but the rubber part stays with the prop. I think I'm going to buy another hub kit to have on hand but I plan on using the existing one to "test drive" the new one to see how it performs.

Going from a 23 to a 19 pitch prop I expect a bit of increased acceleration but less top speed. If I can hit 45 MPH with the spare I'll be happy!

 

[Fun Times]

Re: Bought spare prop, but hub looks different

Tom, the kit you need is merc part number 835257K1 Hub Kits 1 Mercury & Mercruiser Mercury 60-140 HP, V-6,Verado 200-275, Alpha & Bravo under 400 HP $52.50 $49.44

Google the part number for a better price.

http://www.mercruiserparts.com/partsByNumber.asp

 

[etracer68]

Re: Bought spare prop, but hub looks different

Keep an eye on your rpms, you could gain about 400, you dont want to run long, over rated rpms.

 

[TomB985]

Re: Bought spare prop, but hub looks different

Tom, the kit you need is merc part number 835257K1 Hub Kits 1 Mercury & Mercruiser Mercury 60-140 HP, V-6,Verado 200-275, Alpha & Bravo under 400 HP $52.50 $49.44

Google the part number for a better price.

http://www.mercruiserparts.com/partsByNumber.asp

Thank you, Fun Times! This is what I was looking for!

Keep an eye on your rpms, you could gain about 400, you dont want to run long, over rated rpms.

Good point, and that's something I was planning on looking at when I test-run the prop next spring. You really think it could gain 400? That would mean I'd have to be more careful when running it, but that's no big deal to me. I still expect that it'll do over 40, which on an 18' bowrider is more than fast enough for any passengers in the boat! Even though the pitch won't be ideal I still expect that we could still tube and ski with it should I ever need to use it.

 

[etracer68]

Re: Bought spare prop, but hub looks different

Theres always the possibilty that it could, it generally will gain rpms while your trimming up. Im not sure what rpms your running now @ WOT, or what your motor is rated for. I would think somewhere in the 5500 range. Some guys will like the hole shot from a lower pitch prop, and dont run WOT, maybe 7/8ths, watch rpms, and there happy.

 

[TomB985]

Re: Bought spare prop, but hub looks different

Theres always the possibilty that it could, it generally will gain rpms while your trimming up. Im not sure what rpms your running now @ WOT, or what your motor is rated for. I would think somewhere in the 5500 range. Some guys will like the hole shot from a lower pitch prop, and dont run WOT, maybe 7/8ths, watch rpms, and there happy.

Right now I see 4,600 RPMs at WOT @ 48 MPH. Engine is rated at a max of 4,800 RPMs max, so I'll have to keep an eye on the tach when I first try the prop. I'm planning on testing it once to see how it performs and then swapping it out for the stock 23P prop. Including the new hub kit and floating prop wrench this should all cost me less than $110!