4 blade vs 3 blade prop pontoon

I have a 2009 2575 rl triple tube with a 225 yamaha that I purchased used last fall. Love the boat,but have a question about the prop.It came with a solas 4 blade 14 1/4 x 17 prop. I know a little about props and know that this prop is great for jumping up on plane or getting a skier up quick,which I'm not concerned about either. I also notice that the wash behind the boat looks like a sunami.I would think that's a combination of the triple pontoon and the 4 blade prop combined wash. I'm thinking a 3 blade may be better as far as top speed and efficiency. I would love any input from anyone with experience in this topic  Thanks,Bob               

Hi Bob,

I have used both a 3 blade and a 4 blade on my pontoon boat. The 4 blade will definitely hold the water and be more responsive. Fuel mileage is usually a little better and you can usually run the motor a hole or so higher. The 3 blades I have run tend to offer more top speed, seems to plane in about the same time. To get the best of both worlds you really need to try them as much of a pain as that can be. Plus you need to figure what you want from the boat to get a direction. As crazy as it sounds I used to run Mercury hi-five on my runabout and loved it to death, haven't stuck my neck out for that one on the pontoon yet!

Thanks for your response.I'm leaning toward keeping the solas 4 blade.Was just wondering if a 3 would cut down on the size of the wash behind the boat.I pulled a tube the other day with a 50 ' rope and the riders got a lot of spray from the wash making it a little uncomfortable,so if a 3 blade wouldn't change that I can go to a 75' ski rope and that should get them away from the spray.The 4 blade is so responsive I'd kinda like to keep that.     Just wanted some input from people like you.

thanks,Bob

Keep the 4 blade and get a 60' rope for the tube!

Uh, I would seriously recommend a 3 blade prop.  I run a 2005 2575 RL I/O (see specs below) and two years ago I fooled around with several different props (and I posted all the data on this site) and the one 4 blade prop I did try was horrible.  The RPMs were way too high....at an unsafe level actually despite the diameter being what the prop specialist said was needed.  You said yourself that you're not concerned with either fast planning or pulling skiers however with my set up (3 blade prop) I am able to do both.  Best thing to do is try a 3 blade and see if you like it or not.  You can call and order from Prop Gods in Florida like I did.  They'll let you buy it and try it and then if you don't like it they'll buy it back from you minus a little of the full price.

I'd definitely go with a longer rope if that's the only issue! I always used what I thought was a 75' rope, maybe it was a 60'?? If I could get the right combination of pitch/diameter/rpm I'd run a 4 blade all day long. You can also check your mounting height and lower it one hole if possible

thanks for all the input! My neighbor has a premier with a 3 blade he said I could try ,so with that being said I'll see what difference it makes and go from there,but as of this moment I'm leaning toward keeping the 4 blade. Don't really plan on doing much tubing on the pontoon anyway,but if we do I'll use a longer rope.   Thanks again

I know my motor isn't the size of yours but I have the 3 blade 15P and the 4 blade 13P. I ran a little experiment, and well, the 4 blade is back on. They ran about the same numbers as far as speed at WOT, with exception of the little difference in the RPM. The only thing I dislike about the 4 blade is the very low speed vibration (just above idle). As soon as I give it a little more throttle, it stops, but through no wake zones, I tend to put in the vibration zone if the LEO is close by. They stopped me on my first outing because I was leaving "ripples" in the water. I was going upstream, and any slower, I would have been floating downstream. Guess they were having a bad day, that day.

I know my motor isn't the size of yours but I have the 3 blade 15P and the 4 blade 13P. I ran a little experiment, and well, the 4 blade is back on. They ran about the same numbers as far as speed at WOT, with exception of the little difference in the RPM. The only thing I dislike about the 4 blade is the very low speed vibration (just above idle). As soon as I give it a little more throttle, it stops, but through no wake zones, I tend to put in the vibration zone if the LEO is close by. They stopped me on my first outing because I was leaving "ripples" in the water. I was going upstream, and any slower, I would have been floating downstream. Guess they were having a bad day, that day.

Remove the prop and pack it with grease. The vibration/rattle will go away.

What part are you packing with grease?

I didn't put any on the shaft when I installed the prop and shaft was dry.

Put some right on the shaft then put the prop on.  This MUST be done.

You want the prop shaft nice and gooey.

Funny you guys are mentioning this vibration. I am having it on my black and shiny 150 at idle speed. It literally feels like someone pulled a spark plug wire off. It has a 3 blade SS Enertia prop. It will sometimes smooth itself out on its own. I haven't figured out how to manually take it out of vibration mode (varying RPMs, throttling back differently, etc.).

You really think I need more grease? Anyone else experiencing this anomaly?

Should have bought a Yamaha with the sds hub! 

Randy, pack plenty of grease in the plastic hub and it'll be fine. It's the 4 cylinder, it happens on my Honda also.

Randy, pack plenty of grease in the plastic hub and it'll be fine. It's the 4 cylinder, it happens on my Honda also.

Thanks for the advice, Carl. Most of the grease I have observed was on the splines of the shaft.

I'm sure going to give it a try. Thanks guys!

Do you use the special blue grease?

Thanks for the advice, Carl. Most of the grease I have observed was on the splines of the shaft.

That's exactly what I do as well.