1997 240DA SS Prop Recomendation

[FiremistSLK_old]

The 240DA I just bought has the 5.7l Alpha, 260 HP carborated engine with the Alpha l gen. 2 outdrive. It was sold to me with a three blade aluminum prop. The propeller does not look new, but maybe it was painted because there is no paint scuffes off the blades?? I cannot see any markings on it for pitch or diameter. During the sea trial, it was discovered that the tachometer in the boat was not working, so I do not know the RPMs at cruise or WOT. Can someone recommend the correct pitch and diameter and maybe the best make for a SS prop for this family cruiser? I will usually have two adults and three small grandkids on board. Thanks again, JOHN

 

[BillK2632]

The SeaRay website has a lot of information in their archives (http://global.searay.com/page.aspx/pageid/163674/infoLocation/Propeller Charts/Owners-Resources.aspx#PartsandAccessories)
You can down load manuals and brochures for all SeaRay models, going back to 1960. There is also a propeller chart you can download that lists the original propellers shipped with each model. In your case, if you cannot determine what propeller is on the boat, I would start there. Most propellers have the size/pitch stamped on the outside or inside of the hub somewhere. It's going to be something like 14x23, where 14 is the diameter and 23 is the pitch.

According to the chart, your boat shipped with a 141/2" x 17P aluminum propeller.

Now, here is my advice on the propeller on that boat. Most people tend to want a SS propeller thinking that is always better. But be aware of some major differences.

1. A SS propeller is strong and not forgiving. Hit something and it is more likely to damage the outdrive. But they do tend to have a little better performance, especially in fast, higher powered boats. And they are $$ - about 3x's the cost of aluminum.
2. An aluminum propeller is very forgiving, hit stuff, even small stuff and it will probably get bent. They also have a hub system, so hit something big and hard and you are likely to tear up a relatively inexpensive propeller / hub and not damage the outdrive. An aluminum propeller / hub kit is about 1/3 the cost of a good SS propeller.

3. On a small boat like my bowrider or a small cruiser like yours, the SS propeller is not going to provide any noticeable benefit. Also, if your boat sits in the water an aluminum propeller is not going to create any corrosion issues from having dissimilar metals on the outdrive.

I personally would stick with an aluminum propeller. I actually have two propellers of different pitches for my boat and periodically swap them around, plus I have a spare. At a minimum, if you go with SS, I would figure out the pitch on the aluminum one, maybe have it reconditioned and keep it as a spare - trust me, eventually you will need it.

But, if you want to spend the $$, there is no harm, and they do look nice!

 

[FiremistSLK_old]

WOW! Great answer!! Thank you very much! You just saved me some $$$.. I will stay with the aluminum prop and when I fix the tach (got one on order) I'll check that the engine reaches correct RPM for cruise and WOT. If the RPMs are within limits, I'm staying with the aluminum prop that came with the boat... Mainly because I will be boating in Naragansett Bay for the first time and these will be unfamiliar waters to me and your advise about how unforgiving SS props can be when they strike a submerged object. Thanks again Bill..... John D