Boat Halp

"HammerheadFistpunch" (hammerheadfistpunch) 06/28/2015 at 17:52 • Filed to: Boatlopnik, Halp

1

13

My father in law chewed up the prop on his boat pretty good yesterday and we need a new one for this weekend. I am trying to locate a suitable replacement because the one that is on there does a fair job at this elevation but I can’t for the life of my decipher these numbers and google isn’t much help. Part of the problem is that some of the letters could be numbers and some of there may be points in there. I am used to direct drive and V-drive brass props so this mishmash soup on this prop has me confused. Any help deciphering? Also, I assume that a LH engine rotation means an LH prop rotation, right? for more confusion, there is a replacement prop in the boat that looks like this.

The first number you can’t make out is a 4. They are obviously different props and i can’t tell if i need to get a replacement of the same size as the chewed up one, or if this one will work fine. I think this says its a LH prop with a variable pitch of 24-23 and that the chewed up one is a 17-18

Birddog > HammerheadFistpunch 06/28/2015 at 18:03

0

There’s a prop on Ebay with that same PN.

http://m.ebay.com/itm/Mercury-me…

KusabiSensei - Captain of the Toronto Maple Leafs > HammerheadFistpunch 06/28/2015 at 18:14

0

The blade pitch shouldn’t affect things all that much, so long as it is within the manufacturer’s specification.

Inboard/Outboard/Stern drive and manufacturer?

4muddyfeet - bare knuckle with an EZ30 > HammerheadFistpunch 06/28/2015 at 18:15

1

If it’s got the same number of splines then it should fit, I’m sure you’re aware that with different pitch it will change the characteristics of the acceleration, trim tabs (maybe), and change the load on the engine and shaft. If you’re desperate and have to use it then do so, but take it easy. Check your thrust washers while its off too :)

HammerheadFistpunch > KusabiSensei - Captain of the Toronto Maple Leafs 06/28/2015 at 19:04

0

Late 80s mercruiser 4.3 with alpha one stern drive

911e46z06 > HammerheadFistpunch 06/28/2015 at 19:28

0

Should be fine. If not get the old one, grind that fucker down, and slap it back on.

HammerheadFistpunch > 4muddyfeet - bare knuckle with an EZ30 06/28/2015 at 21:26

0

Its a 5 inch pitch change which is a lot for a v6 at 6000 feet

4muddyfeet - bare knuckle with an EZ30 > HammerheadFistpunch 06/29/2015 at 04:05

0

It is, but it depends on what your manufacturer recommendations are. A quick search for your engine brought up upto 29 inch pitch on a triple bladed stainless prop, whereas the aluminium props finish at 25. This is wholly dependant on conditions, craft mass, and they both require a trim anode. You’ll have to find the spec sheet for your motor and stern drive to see what is actually required if you want to run it at max revs, but if you just need to potter about on the water for a bit the second prop will work, I just don’t know how she’ll handle. You can probably expect to lose around 100-150 rpm per inch of pitch added. As far as you can tell, is the diameter the same?

HammerheadFistpunch > 4muddyfeet - bare knuckle with an EZ30 06/29/2015 at 11:16

0

Diameter is the same. The main problem we face is that we will be at 6000 feet and its a carbed engine. those 175 sea level horses will be more like 135 when all is said and done. and seeing as how top end is meaningless for this like and that we will want to pull skiers and such I think going from a 17p to a 24p would be a bridge too far. My father in law is coming by the house today to take the old one off and take it in to be matched. Its very “undergeared” for sea level use but would work really well at elevation I think.

4muddyfeet - bare knuckle with an EZ30 > HammerheadFistpunch 06/29/2015 at 14:42

0

Fair enough, better to be safe than sorry. There’s a couple floating (intended) about on eBay with the part number 48-78118-17 if you get stuck buying locally.

HammerheadFistpunch > 4muddyfeet - bare knuckle with an EZ30 06/29/2015 at 14:46

0

thats plan b, but we have a farily robust boating community in the 2nd driest state in the nation for some reason

4muddyfeet - bare knuckle with an EZ30 > HammerheadFistpunch 06/29/2015 at 14:54

0

Oh I meant to say: you can also get the blades bent by a shop if you have no other option. Not all the way down to 17, but at least an inch or two if its aluminium.

Boatboy78 > HammerheadFistpunch 07/01/2015 at 14:13

0

The 48-78118 number is the part number from Mercury/Quicksilver for the propeller. Quicksilver is to MerCruiser as Mopar is to Chrysler or Motorcraft is to Ford.

Quicksilver has different designations for OEM parts with the first two numbers. For example, all OEM Quicksilver propellers start their part numbers with a “48”. Oil and fuel filters start their part numbers with a “35”. For example, a fuel filter for that particular engine (4.3 Liter V6 Chevy) has a part number of 35-807172. Gaskets start with a “27” number.

The other numbers after the first two digits only count as a part number in the Quicksilver parts catalog. They don’t decipher like a VIN number.

You have a few choices:

1. If you are in a town with a marine propeller repair shop, they may be able to repair the prop. I am assuming the prop is aluminum. Aluminum props are easy to repair. If not, they should be able to sell you a new or used prop for less than you could buy it from a MerCruiser dealer or a retail boating supply shop.

2. Go to a boat dealer and see what they have. MerCruiser is the most popular stern drive in the country and most dealers stock their parts. They might have a factory replacement in stock. Most dealers stock props because they get damaged a lot, especially with new boat buyers that are new to boating. At the very least, a dealer can run that part number and tell you the size and pitch of the prop, so you know what you have.

3. Craigslist or Ebay. If you know what you have, there is always a chance you can find a prop there.

If the prop worked well before, stick with what works. Changing prop pitch can be a long process, as finding the best, all-around prop can be time-consuming.

HammerheadFistpunch > Boatboy78 07/01/2015 at 14:15

0

option 1 was the path we took. Thanks for the info though, I knew those numbers had to mean something. as for pitch, we aren’t going to bother, he bought this boat on the classifieds for $3500 and plans on selling it after this reunion.