I bought a newer boat last year, 14.5ft 1985 model with a 85hp engine. Then my friend needed some money now for his new Saltwater boat so he gave me a really good deal on his old 16ft bass boat with a 115hp motor. I am going to sell the 85hp boat but i had a question about the props. the 85hp motor has a stainless steel 3 blade prop with no dings and just about brand new looking. The newer boat with the 115hp prop has a 4 blade aluminum prop that has been dinged up. My friend said when their is two people in the boat it takes a little bit to plane out because so much weivht is in the back (fuel tank, batteries, etc...). he has the fins you can attach to the lower unit but never got around to put them on. Doesnt that help plane out quicker?

but to my prop question. I have read that 4 blades are better at lower speeds (taking off, crusing, turning) & 3 blades give you higher top end speeds. I have also read that Stainless Steel props are the best vs aluminum. So my question is which would you rather have on your boat a 4 blade aluminum (I would look to replace the dented with same) or a 3 blade stainless steel prop?

I am no expert but here is my opinion,

It is really a little bit more complicated than just 3 blade vs 4 blade. Your prop should allow your engine to reach maximum wide open throttle (***) RPM. Most engines that is around 5500. I am not sure about yours. Stainless steel is superior to aluminum. The blades are thinner and stronger.

You are correct about 3 blades generally speaking giving more top speed, and 4 blades better bite in rough conditions and turning.

I would take a 3 blade SS prop,but the prop for that 85HP motor may not be the right diameter and pitch for the 115. It will probably be a bit small causing the 115 to over rev.. Also, different motor brands props don't always match up(splines).

My two cents worth?

Leave the boat you are selling just as it is now. A nice used prop that isn't all chewed up is going to be a plus to any buyer. It shows that you weren't rough on it which is the issue you yourself have with this newer boat.

As far as this newer boat goes, I would install the tail first. These things are designed to provide you with extra lift that will give you a faster hole shot. That is obviously an issue your buddy had with it. Then its going to be time to find that right prop to help you get the most out of the 115hp. It might end up being a 3-Blade or a newer 4-Blade. In my experience, every brand of boat/motor combination will have a number of props that will solve one problem (hole shot -vs- top end speed) while causing another. You would probably be better off to look for something fits your style within the limitations your boat has.

SS props - Aluminum? My best advice is to take that beat up prop to your local mechanic and ask him what that engine would be like if those dents where in a SS version. Aluminum props provide a little more protection for the rest of your outboard if you are running your boat in waters where hitting obstructions is inevitable. Cheaper to replace a blade than an entire drive shaft.

3 blades will usually help with bow lift and a little more speed. 4 blade will be better for stern lift. not always the case but usually when someone uses a whaletail, it's because the boat is'nt set up correctly. I have a 115 and run a 13x19 4 blade ss. this is on a 19' alum. bass boat. I tried a 20p 3 blade and could'nt get enough rpm's. no one can tell you what prop to get without more info. a lot of times, several props will have to be tried to get the best one for your boat.

With an aluminum prop, you probably won't notice much of a difference, no matter which you get. A four blade usually helps a little on hole shot but will cost you a couple of mph on top end. I have a feeling if you stuck the proper pitch raker on it it, and the motor is good, you would be more than happy.

Look on the end of the prop you have now and see what size/pitch it is. You may have to take the nut off because sometimes the washer under it will cover the numbers up. You should see something like 13 1/4 x 19, which will be the diameter and pitch. Understand, I'm not saying that's the size your's is, I was just using those numbers as an example

The next thing you have to look at is how many rpm you're turning with your current prop at WOT. If you are not turning 5,300 or more, you need to go down one pitch size, for instance from a 19 to a 17. If you are only turning 4,800, you may need to drop down two sizes or possibly check you motor out, make sure it's good.

The blades on aluminum props fold back so much under a strain, like hole shot and WOT, there is no way they can provide any kind of performance.

Also understand, not all SS props are created equal. Your standard SST prop is nothing but a general duty SS prop, make to the same specs as the aluminum. You need to be looking at the Raker's II's or Renegades if you are working with a Johnson or Evinrude, if it's a Merc, can't help you there.

In my experience an aluminum prop is a mistake. They get chewed up from junk in the water and if it ever scrapes during trailering or loading it will break. The advice above is very good. And a prop that is cupped will give more high end thrust. 4 blade will be more fuel efficient but 3 blade will be more a balance of high and low thrust. Knowing your peak hp rpm you can visit a website and pick the right pitch etc.

My friend would always make a half cast of his prop in concrete (cut down 5 gal bucket filled with concrete then prop pressed into firm concrete for shape) so he could pound out inevitable bends.

The 3 blade yes is better top end, and the 4 blade gets outbid the hole quicker and stays ontop of the water higher. By its all about how your boat is some boats with a 4 blade will turn to high rpm's and will blow your m

Motor and as far as stainless vs aluminum def. stainless. When I comes to props you just have to try them.