Help me pick a prop...

Yea, I find it hard to believe that didn't catch that either. However, with the flooding of communication that took place, there may have been a communication error such as them thinking 150 when you said 115. Don't know what part of the country your in, but with my terrible southern accent, I have had that problem when I had my other boat with the 115. There were several times I would tell someone I had a 115 and would think I said 150:)
 
Good thought, but I don't think there was any miscommunication. We talked about the gear ratios being 2.07 for Mercury's 115 up until they recently changed to 2.33, which is what I have. I think the 150 gear ratio is 1.9 something. It could be some other kind of misunderstanding though. Still glad I didn't place an order, although I'm sure they would have made it right.
 
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Bigtop is correct about the clearance issue. The other issue is that the prop hub diameter is different for each gearcase.

I would stick with the 13p since you're already at the top of your engines rpm range with the Black Max 15p. The pontoon series Spitfire 13.8 x 13p would be a good choice in aluminum if you want a Mercury prop. You're looking to pull tubes with a loaded boat. A four blade works great.

I'm definitely NOT a PowerTech fan, but to their credit, I do believe that the fella knows the gearcase diameter differences and made a honest mistake with his recommendation.
 
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Ordered the Spitfire 13.8 x 13P today. I ran different scenarios through Mercury's online Prop Selector, and the best I can recall what my poorest performance stats were from last season with a heavily loaded boat, the prop selector put me right on the fence between the 13P and the 11P. I decided to try the 13P first, as I'm hoping it will improve my heavy-boat performance while not making me hit the rev limiter as frequently with a light boat. I may end up ordering a 11P later, then sell which ever one I don't keep on ebay or Amazon.

Here's what I learned so far, to those reading this - If you are debating between a 115 or 150, like someone asked today, go with the 150. If you already have a 115 HP (or smaller), or are planning to buy a 115 - You may not want to put so much stock in the top speed numbers, especially if you plan to pull tubes with it. Maybe going after the best 0-20 mph acceleration time would be more appropriate. If you are about to buy a new boat with a 115, you may want to have your dealer do some prop testing with you BEFORE you buy the boat.

It may be a couple weeks before I can run my old and new props under heavy load to compare numbers, but I'll come back and post the results when I do.

Thanks for everyone's comments so far.
 
If it means anything, I think you made the right choice. Best if luck. Your exactly right about those on the fence with the 115 or 150 to go with the 150. There has been a lot of discussion on that. I was fortunate in the fact that after I purchased my first boat with the 115, I was able to go back the next year and got a great deal trading it in on another same year demo boat witha 150.
 
Well, the Spitfire came this week, and we tested it out today. I was very impressed to say the least. Big improvement.

I wasn't really able to take stats today, but the acceleration was amazing, and we only lost a few mph (2-3) on the top end speed.

I went from a 13.75 x 15p Black Max (3-blade) to the new 13.8 x 13p Spitfire (4-blade). My WOT rpms didn't change, still at 6400 rpms with 4 adults and 2 kids. I'm sure with just our family (2 adults, 2 kids) I will hit the rev limiter, but not by much. The REAL difference came with a loaded boat. We had 10 on the boat (5 adults, 2 teenagers, and 3 younger kids) and we had more speed than I needed when the two teenagers and one little kid went out on the tube. Let me repeat that - I had throttle to spare! Woo-hoo! Not much, but MUCH better performance than the old prop. Acceleration was very noticeable. The motor wound right up to the 5000 rpm range in just a couple seconds. Amazing.

Had I had an even heavier boat, I'm sure the steeper 11p Spitfire would have been a better choice yet, but since we also often have a light boat, I think the 13p Spitfire is good middle ground between having more torque for a heavier boat, but not having to worry much about over-revving with a light boat. I can just run the one prop and not have to change them depending on the kind of boating we plan to do.

Okay, I still would recommend a 150 over a 115, but for those that already have a 115 and are somewhat disappointed, the Spitfire pushed me just over the edge of the fence into the "good enough that I won't be upgrading to a 150 anytime soon" side of the fence. Not bad for a $150 prop. It lives up to the hype in all the ads. And I now understand why I've never read anything bad about it.

One other thing - the prop didn't ventilate on me either. With the Black Max, I had to be trimmed all the way in/down when turning with a heavy boat and a couple kids on the tube or it would ventilate. Matter of fact, it would still ventilate on me occasionally even if I was trimmed in all the way. With the Spitfire, I was trimmed up to the optimal range for my speed, and I didn't have to trim down AT ALL before I made a turn. No ventilation at all. Awesome. Awesome. Awesome. Much easier to drive while pulling a tube. Not having to precisely dial in the trim constantly while tubing is just one less thing to worry about.

So, yeah, I'm thrilled with this prop. No question.
 
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I love it when a plan comes together!
 
You may have just saddened many dealers! Now everyone that reads your post will only spend $150 on a new prop instead of trading in and upgrading!! Haha good for you though!
 
You guys will not believe this. I almost can't believe it myself. The wife just told me she wants the boat to have a 150. I am dead serious.

I also have someone interested in my 115 already.

So, same song, second verse... What prop should I get with the 150???

An Enertia, I assume, but size/pitch???

I am as stunned as anyone, but may have to move quick before she changes her mind...

Happy 4th. Heading out to the lake shortly.
 
Congrats on your decision, and to your wife. The 15 x 15 would be my choice.
 
Kaydano, would you please have your wife call my wife and talk to her?
 
WHY ARE YOU ON HERE? GO BUY A 150!!!! Once you have it she can't change her mind!!
 
Kay.............."Happy 4th", "Happy Labor Day", "Happy Thanksgiving", "Happy Birthday" and "Merry Christmas"!!!!!!!!!!! What do 150s go for?????? Curious.........
 
Ha ha ha. I'm trying to figure out how the new motor will be HER b-day and Christmas present instead of mine! There will be no mention of this until AFTER the motor is attached to the boat of course.

$9-10k range, plus or minus. Hoping it will be minus. No idea what my trade-in would be, so I might sell it outright. Hoping my incremental cost is under $3k.

I plan to try it without power steering first, and then add that later if it's really hard to turn.
 
Start working out your left arm and left wrist, the right one will be on the throttle! Haha
 
I

You guys will not believe this. I almost can't believe it myself. The wife just told me she wants the boat to have a 150. I am dead serious.

I also have someone interested in my 115 already.

So, same song, second verse... What prop should I get with the 150???

An Enertia, I assume, but size/pitch???

I am as stunned as anyone, but may have to move quick before she changes her mind...

Happy 4th. Heading out to the lake shortly.
Get the conversation on video and in writing!!!!!!!
 
Kaydano, once it's said and done, neither of you will ever doubt the decision to go with the 150.

BTW, I drove the identical boat to yours last year, only it WAS powered by the new Mercury 150 four stroke. If I recall correctly, we had 4 people on board and ran about 38-39 mph. It had an aluminum prop that wasn't ideal that's for sure, as it had a slight cavitation at WOT. I have little doubt that with a better prop the boat will easily top 40mph. The most notable difference will be in the huge gain in torque over your 115. The new Merc 150 is a 3.0L. Big cubes equals big torque. You're gonna love it!
 
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We have a couple of families with Brand H tri-toons here on our lake and the new Merc 150's. They both tube a LOT, as in almost full time, and absolutely love that motor. I also drove a demo Benny with it last year and was very impressed, particularly for the price point.
 
Kaydano, once it's said and done, neither of you will ever doubt the decision to go with the 150.

BTW, I drove the identical boat to yours last year, only it WAS powered by the new Mercury 150 four stroke. If I recall correctly, we had 4 people on board and ran about 38-39 mph. It had an aluminum prop that wasn't ideal that's for sure, as it had a slight cavitation at WOT. I have little doubt that with a better prop the boat will easily top 40mph. The most notable difference will be in the huge gain in torque over your 115. The new Merc 150 is a 3.0L. Big cubes equals big torque. You're gonna love it!
Thanks for the info, that helps a lot. I've had some thoughts (just a few) hoping we didn't get the 150 and STILL being disappointed with it, although I have NEVER heard anyone say this on this forum. So, your comments help me think the 150 is the right thing to do. I did notice the 150 is a 3 liter the other night. The 115 is a 1.8 liter. That does mean a better torque curve at lower (mid) RPMs.
 
We have a couple of families with Brand H tri-toons here on our lake and the new Merc 150's. They both tube a LOT, as in almost full time, and absolutely love that motor. I also drove a demo Benny with it last year and was very impressed, particularly for the price point.
That is really good to hear. I very much appreciate yours and Ben & Suzy's comments on this.

We learned the last few outings that loading the back of the boat with passengers WORSENS the tubing performance. This is counter to what I had thought. We had 7 passengers Wednesday (mostly kids), and tubing was on the sluggish side. That night, we were wondering why that was, since last Sunday when we had 8 on the boat, with more adults than kids that time, and tubing seemed quite a bit better that day. I actually had throttle to spare. That was the night I wrote my glowing Spitfire review. Yesterday (Friday) we went out with 8 again, which were the exact same 7 people as Wednesday, plus one more mom. I put 2-3 people on the bow couches this time, and tubing performance was a LOT better with 1 MORE adult on board! This is counter to everything I've read about weight distribution, but the boat must have been plowing too much with all the weight toward the back? And no, it wasn't for lack of dialing in the trim. I was constantly changing trim to improve performance, but no luck. So even with 1 more person, by putting some of them up front, it actually made things noticeably better than with one LESS person and all of them concentrated to stern. Weird, but the wife and I both could tell a difference.

Bottom line is the 115 is very borderline for "exciting" tubing. Being borderline, we found rough water is much better than smooth water, if your goal is to bounce teenagers around on a tube. The Spitfire prop is WELL worth the money if you already have a 115.

Our kids are 10 and 14, and they will only get bigger and heavier. Their friends will get bigger and heavier too, so we see upgrading to the 150 as being inevitable, and since our new 115 is depreciating fast, we're gonna get the 150 soon.

Anyway, the reason for writing all this is to help anyone trying to decide between the 115 and 150. Go with the 150.
 
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