Show us your BOAT!!!

We did some looking around at the basics and nothing stood out as obvious. It's now back at the dealer for warranty repair again.

 

Picked this up a few months ago up in Washington, never tow a boat for 13hrs…

 

Oh yeah, if you have a warranty then let them deal with it. These new age 4 stroke outboards are crazy simple, but they also have some odd methods of operation in some cases as well. They'll get you sorted it out, they probably see it often.

 

Unfortunately the FJ no longer exists .. but on the positive side it has been replaced by a 2017 Tacoma as the tow vehicle..

 

Why SS for a 40 HP? Not like it can get any performance advantage over an aluminum with the same pitch and diameter right?

 

Can't say for certain because I went with a different size and pitch with the new prop, but the main reason I swapped was because the aluminum prop it came with was already getting chewed up from knocking stumps (Louisiana waterways are extremely stumpy for the most part). I never took a high speed hit or anything I cringed at and I had 1/8" dings in several places which was obnoxious and risked causing damage if the prop became too unbalanced. The new one should withstand all those low speed soft stump hits no problem, and switching specs on it happened to give me some improvements as well.

 

That's not true. SS props have more cup which in some situations prevents water blowout or prop aeration. It won't help every time as it is dependent on the hull design and load the hull sees, but if you have a light boat and a hull built for it, hell yeah a SS prop will help.

Example: my rig was designed to have a maximum HP motor of 50HP, but I upped the horsepower to 60 as the Mercury 50/60 motor as the same 995cc motors, so with that I also added a stainless prop and where I used to top out around 35-36 mph with just me in it loaded down I now top out at 43.5 mph loaded down with just me in it.

It's like I previously mentioned to someone else, it may not be THE solution but it is a part that contributes to a greater whole.

 

If the SS will stand up to those type hits I guess that makes sense, wouldn't think it would though.

Interesting, didn't know they had more cup. I just know those low horse power motors don't benefit from the stiffness since they don't have the power to flex even an aluminum prop. You changed the motor AND prop and got the extra speed or just changed to a SS prop and got the extra speed?

 

It's not really a fair comparison between a stainless and aluminum prop when you also add in a 20% increase in horsepower. If you didn't also change the pitch of the prop when upgrading to match the new engine then you had the wrong prop on the 50hp in the first place which would hurt its performance.

For me I don't see the benefit of a stainless prop outside of high horsepower or saltwater applications. They cost 3x as much but don't provide me any benefit that's worth 3x the price. If I were constantly hitting stumps with my prop maybe, but I don't play that game.

 

They generally do, and it's cheaper than a new alu prop to have a SS one repaired. Perhaps this stock prop was particularly garbage, but there was no way I was keeping this piece of junk on my motor lol. I'll try to take a pic later.

 

Oh that's not been my experience. I think it's a couple hundred at least to repair a SS prop and you can buy an aluminum for around $80-100. 150 HP though so maybe that makes a difference.

 

I’d never owned a CNC’d prop until last week. They are serious works of art that are a ton of fun to look at in detail.

 

I know a guy.

 

I personally don't run SS props in my area because if you hit a rock, they transfer far more of the shock to the lower unit.

 

I didn't change the motor, I just unlocked more airflow from it by removing and installing some things required to do the conversion. By doing so it increased the RPM with the OE prop by about 300-350 which was enough to kick in it's guardian mode so I was forced to change props. So I changed it out of necessity, but I figured I might as well throw in a nice stainless unit on there, so I did just that and it put me back within the upper tier of the 5500-6000 RPM sweet spot. OE size was 14 pitch aluminum so I went 15 pitch stainless. Then I did my jackplate which raised me up another 125 RPM at wide open, so I'm back up to 6000. Lol. I'm still within the powerband range though.

The right pitch prop was on there to start. It was factory matched based on the boat design, but then I went and screwed around to make it wrong, so when I increased airflow, I increased pitch to keep me in the correct powerband range.

That is true, but it depends on what sort of propeller you run as well. Do you own a Merc engine? If you do, and you run a Merc stainless prop, their Flo Torq hub bushing is designed to allow the prop to either slip, or get damaged in the event you do hit something with the prop. Saving your lower unit and your prop. So instead of paying $1000-$3000 for a new lower unit or even $300+ for a new stainless propeller, you are spending only some $20-$30 to replace the damaged hub.

 

So you made changes to your engine and prop pitch and got more speed. Has nothing to do with the material of your prop. If you want to spend the added money on it for how shiny it is, rock on. But there is no justifiable performance benefit on a motor with low HP like that.

 

At what hp range does it make sense to go stainless?

 

150 for sure, possibly 115 but not sure if even a 115 can flex an aluminum prop enough to make a huge difference.

 

Oo that's a pretty motor.

Not true. It may or may not have helped. The only way I could give you the answer as to whether or not it did, would be to use an aluminum prop that is equal to the RPM I have no and see what it runs at. I don't want to spend more money on props though, as I already have two. (Unless you want to send me one for test purposes. Lol)

Regardless, the way it performs is better than the aluminum unit and because it is able to be designed differently from it's aluminum counterpart, you get more benefits from it aside from speed. If you are going for holeshot, because the SS is designed the way it is, it also gives you a better holeshot as well.

Speed wise you may gain 1-2 mph. Some motors even 3-4 mph.