Sound reasonable??

[Renegade]

I have a 2014 South Bay 22' 522cre with a 4 stroke 115hp Merc. The boat is a two toon with no strakes. I do have sea legs on it which I think adds 150lbs if I remember right. At full throttle I'm hitting 21mph on my gps fishfinder unit. Does that seem reasonable? I was thinking I should be in the high or at least mid 20's with it. The speed was taken under calm lake conditions with just my wife and 4 year old son on board. This is my 3rd toon and I can never seem to get the speed that other members here seem to be getting. I really haven't played around with motor hieghts and props either though. What do you guys think?
Also, at about 3/4 throttle and up I hit 7000 rpm (it tops out there) without getting a rev limiter warning. That is on the new "all in one" computer moniter display unit on the new South Bays.

[dodger]

Check the sealegs website, but, I think they weight a lot more than 150 lbs. Plus they are hanging down there under the frame and catch a lot of turbulent water.

We had considered them at one time as well, but, the weight and drag factor ruled them out for us.

[Waterlogged]

I think you should try to avoid revving to 7000 rpm, If you check it out I would bet max recommended rpm is in the neighborhood of 6400 rpm. I'm surprised the rev limiter doesn't cut in before 7000.

Glenn

[Renegade]

I guess I was off a bit with the weight of the Sea Legs. They are 386lbs so that will definately play a factor. I was hoping somebody here would have a similar set up and could let me know what they are getting for speed.
As for the RPM's I don't think it's actually hitting 7000, I'm leaning more to the display being out. Doesn't sound like it's reving too hard and every other motor that I've owned has a rev limiter alarm. I'm not getting any kind of warnings.

[smoker62]

My 2012 SB 522- merc 115 4 stroke, did 25 mph gps on a good day. Propped correctly, twin toon no strakes but underskinning. This with myself and my wife. I am 325# , she is 130#. Your rev limiter will kick in above 6400 or so If I remember correctly. Its not an alarm but a slight miss in the engine firing. I ran a 13 pitch spitfire 4 blade. What pitch are you running now ?

[pelicantooner]

My 22' with a Yamaha 115, no strakes or under skin. I have hit 26mph. Really with 4 adults, closer to 21 - 22 mph.
There is really lots of drag underneath with it not having the under skin. My next will for sure have that.
We have lots of pontoons on the lake with the sea-legs, and I can see where that would also slow you down with the waves catching them.

[onthelaketwo]

I top out slightly above 21 mph GPS

24 foot manitou , 90hp etec, 14x11 prop, 5000 rpm, and SEALEGS plus 2 batteries and 300 pounds of passengers and full tank gas

[STEVEBRENDA]

Sounds like you have the wrong prop. What size and pitch do you have?

[jayw]

Don't know about this newfangled computerized stuff but sounds to me like the tach is out of calibration, to start. If it were an analog tach you would check the tach pole setting, wiring and ground. It's under warranty, best you call your dealer and have them track down the tach issue. I'm no mechanic but I can tell you, that 115 would probably blow something if you were hitting 7K esp. sustained! It's rated for 6000 or maybe 6400RPM. In short, you are most surely not hitting 7K. My guess is you are hitting some much lower number.

Are you runnng a 13P prop? With your setup -sea legs on a 2 toon boat, I would try to run a 4 blade prop. Maybe a Turning Point Legacy if you are going aluminum. Probably appropriate given your setup. You may actually be running too LOW in RPMs and that's causing your performance issue, while the tach issue is throwing you off track. My amateur guess: you have 2 problems.

I would think you could do a bit better than that with that motor but remember, a 2 toon boat acts more like a displacement hull, while the tritoons (esp with strakes) that can "stand up" act more like planing hulls these days. That's the goal of the tritoon: get the boat to act more like a planing hull.

[rockhound]

first 7000 is way too much rpm,

i too a look at your sea legs product, I had never seen them. They look nice product if you can tie up or dock behind the your house, I dont see the use otherwise, but they hang down 5 inches below the deck or underskinning, that is a lot of drag to overcome,

i would think that you would want to look at some way to keep the water off of them while underway,

you might be a candidate for some tap fins...... I probably get flogged for that one

[Renegade]

Thanks for the replies. It's a 13p prop. Yeah I'm sure the tach isn't reading properly. I'll try a different prop I guess and go from there. By the looks of some of the other speeds you guys are getting I guess it doesn't seem too far off. Just was expecting more I guess. My last 22' Bennington with a 115 hp optimax was getting about 26mph with sealegs on it as well.