prop recommendation

[WillyC]

I'm looking for a few suggestions on what prop to buy. The boat is a 1975 20' sf. Transom has been rebuilt to 25". I bought a used 1993 yamaha 200 carbarated motor and I'm thinking I should start with either a 14 1/2 by 21 pitch or a 14 1/2 by 19 pitch - both three blade. The boat will be set up with trim tabs and will be fairly light with no t-top. Thanks -will

[bunderwood]

I just replaced my prop...I have a 20 sf 1979 with a 150 merc. The prop that was on it was a 14 17 pitch. Max RPM's with that prop was 4900. I spun the prop and thought it was good time to change size so I went with 14.5 19 p and gained about 200-300 more rpm.

[eggsuckindog]

Tough call, I have a 19 on a 20MA with a T Top and its right, but your lighter and might swing the 21. Any chance to borrow an Alum 19?

[Bigshrimpin]

Will - Props are very very different . . . it's not just pitch and diameter and matierial. Pitch and Diameter will get you in the ballpark for RPM's, but blade area, blade thickness, rake/geometry, balance, etc have lots to do with getting the right prop for your boat.

I know it probably sounds like a broken record, but the mercury mirage "plus" is best prop I've used so far. The stern lifting characteristics of the prop put the bow down right away. The bow of your boat won't shoot up to the moon out of the hole . . . as it will with bow lifting props. Search the forum and Fr. Franks comments.

I was a big dummy and had to play around with many props, before I bought mirage plus. On Merc's site find a DEMO dealer that will let try different props, before you buy one. Ebay is also a good source.

[WillyC]

Thanks for the replys guys. I forgot to mention that I want a stainless prop as I will be fishing lots of shallow oyster reefs. I was initally thinking of getting one of the yamaha saltwater series props from ebay. I will definitely look for the mercury mirage plus props too. I have a while before the boat will be ready but I would like to be able to jump on a good deal when I see it. Anybody know how those yamaha saltwater series props preform?

[Michael Vezzosi]

Will, for what it's worth, I have a 1982 BW 15 Sport, refurbed and repowered in '05 with an '05 Yam. F60. Factory Yam. SWS (supposedly SS but black powdercoated). At 10.25 X 15, I was constantly bouncing off the rev. limitor due to the manual jack plate I also intalled. 61-6200 rev.s depending on wind and current.

After much research on the Whaler forum, I purchased a Hot Shot Turbo 10.5 X 16, which, I am told, usually runs more like a 17. The overall weight, size and thickness of new prop is significantly larger/heavier.

What I found was worlds of difference. Factory prop was light with thinner blades, wound up quickly, and made the boat quick, light and nimble, if you will.

New prop almost literal translation. Heavier, more stable, and longer to wind up. Example, slightest wake at full throttle, would initiate violent chinewalking ( on the edge before any hint of wind or wake). Back off throttle while trimming back down in anticipation, and was not that delayed. (With factory prop).

New prop brought down chinewalking, delayed response of throttle and trim, but more solid transition of wakes, then dumping throttle, trimming back out was delayed considerably and took longer to wind rpm's back up.

Bottom line? Still turning 46-47 mph, but revs no higher than 5800. Still trying to pick up speed without rev's.

If you want, try www.thehulltruth.com. PeterB is working with same guy I use over at www.continuouswave.com, Tom W Clark. A wealth of knowledge, can get almost any prop you want to try, and sells them cheaper than ebay. He lurks all prop questions, just does not own a classic SeaCraft...

Hope this helps. Part II.

[brianmullinax]

selling the boat now,so don't think I am miss leading you. the Merc Mirage Plus is a good prop and gets my 20' classic to a top speed of 54 knots. It holds the water awsomely and gets the boat on plane in no time. I my opion Merc makes the best props, due to their racing background