Prop for 115 2S on SF 20

muddywater · #1 04-05-2007, 02:35 PM

Yesterday I picked up a 72' SF and towed it 500 miles with a 4-cyl standard Toyota Tacoma. I don't recommend anyone else trying this, considering that I could smell my truck burning on the steep hills. I guess it was the clutch. It will be fine when I get it home where everything is flat as a pancake.

Anyway, the boat has an old 115 Mariner that supposedly only has 20 hours which might be true considering it still has paint on prop and lower unit and has not been started in 17 years. One blade on the prop is bent (aluminum prop). Before I go buy a new prop or get this one fixed I wanted to find out if it is the right size. It is a 17 pitch prop (dunno the dia. If you can decipher the serial, it appears to be 48 77344A-4 17P (not certain about that first number though). I would have guessed a 15 pitch prop on a 115 on a 20 SF, but I really dunno. Motor S/N is 5940375. Anybody have any information on this motor? Since it says Fond du Lac, Wis I guess this motor was produced after Merc bought Mariner but I don't know much else about it beside the obvious stuff.

Thanks
-Muddy

caper · #2 04-05-2007, 02:46 PM

I had Yammie 130 hp 2S with a 13" by 19" SS on a '75 20' SF and it was just right.

eggsuckindog · #3 04-05-2007, 05:13 PM

I think my 115 swung a 17 should be right.

Old'sCool · #4 04-05-2007, 06:41 PM

Some of the old Mariners were supposedly built by Yamaha.

muddywater · #5 04-05-2007, 07:10 PM

Thanks everybody for the replies. Keep em coming.

Michigan Wheel has a prop selector program which I entered the information into and it said 13 1/4 x 15 pitch. Of course, a Seacraft 20 is right on the line, so I guess it could go either way (15 or 17). I was thinking about occasionally wakeboarding so the lower pitch prop might be better for me? I was looking at the Rapture props. If you go from Al to Stainless, don't you need to drop pitch if the stainless prop is cupped? I think the Rapture is high rake, which might not be so good for stern lift, but then again, this is an ancient light 115 so I probably don't need to worry about that.

Anybody know any good places to look for cheap props besides Ebay? I saw a couple Rapture props on ebay in the right size and diameter but haven't figured out whether they all work on all manufacturers motors or not (or whether they all have a replaceable hub or not). I could not find any Mirage's or Laser's below 19P (short of buying a $$$ new one).

Oh btw Reelscape, how old were the Mariners that were built by Yammie?

Anyway, thanks again everybody

strick · #6 04-06-2007, 12:49 AM

Hey Muddy-

Congrats that you finally got our boat!!

strick

Bigshrimpin · #7 04-06-2007, 02:46 AM

Quote:

Thanks everybody for the replies. Keep em coming.

Michigan Wheel has a prop selector program which I entered the information into and it said 13 1/4 x 15 pitch. Of course, a Seacraft 20 is right on the line, so I guess it could go either way (15 or 17). I was thinking about occasionally wakeboarding so the lower pitch prop might be better for me? I was looking at the Rapture props. If you go from Al to Stainless, don't you need to drop pitch if the stainless prop is cupped? I think the Rapture is high rake, which might not be so good for stern lift, but then again, this is an ancient light 115 so I probably don't need to worry about that.

Anybody know any good places to look for cheap props besides Ebay? I saw a couple Rapture props on ebay in the right size and diameter but haven't figured out whether they all work on all manufacturers motors or not (or whether they all have a replaceable hub or not). I could not find any Mirage's or Laser's below 19P (short of buying a $$$ new one).

Oh btw Reelscape, how old were the Mariners that were built by Yammie?

Anyway, thanks again everybody

Laser only goes down to 19 Pitch and Mirage plus only fits the large hub Mercs. Try PowerTech . . .

http://www.ptprop.com/catalog/

muddywater · #8 04-06-2007, 03:45 AM

Thanks for the welcome Strick. It's been a long time coming. It's gonna be a while before I can hit the water in this thing. You know how that goes.

Thanks for the heads up on the Mirage and Laser BigShrimpin. I will prob go with a Powertech when I get a new motor. For now, I am just trying to come up with something relatively cheap to stick on this old motor. It looks like I might be able to get a Rapture (SS) for the same price as a new Al prop on Ebay. Will post numbers when I get this thing running.

The motor is actually in inline 6. Since it was a 115, I was thinking 4-cyl before I popped the top. It will definitely need some rewiring, an impeller, and probably a carb kit, new gas lines, filter, steering, yeah.. pretty much everything... Should be fun

Bigshrimpin · #9 04-06-2007, 12:59 PM

muddy - I found the rapture prop to make the bow way too light compared to other props. Your boat may behave somewhat differently since the rapture prop for the inline 6 is a smaller diameter prop with less blade surface, but I didn't like the rapture prop I tried for the 20. I got much much better performance out of a dinged up aluminum blackmax prop (both were 17 pitch and the rapture was in perfect condition)

muddywater · #10 04-06-2007, 04:26 PM

Thanks BigShrimpin! I will skip the Rapture then and see what else I can find.

-Muddy