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S series sps 200 help needed

Bamaman said:
Andy:  When you start to porpoise, just touch the down button slightly.  That should be your most efficient trim for speed.  And if you're pulling 6000 rpm's at that point, you're probably properly propped for all round running.  At 44 mph, I don't know that it's worth the effort to raise the engine as you're up there with the big boys with their 250 ESP hulled boats.

When I got my boat, it came with 14 pitch M series prop.  I was at 6300 rpm's and 3-4 mph slower than I expected.  After going up to the 15 pitch, it was just right.

I grew up 27 steps from the water, and living on the lake has its benefits.  I've run 13' Allison's with 100 Mercs (1969), a couple of tunnel hull boats.  Later, had a bass boat with a 175 hp Merc. Black Max.  Then, a couple of inboard outboards that made me never want another I/O.  And 27 years with a Starcraft 24' with a bulletproof Yamaha 115 hp 2 stroke.  Now we have the Bennington, a SeaDoo and a 4 stroke Waverunner.

I'm about to the end of my boat buying, especially since I don't have anymore space on my dock/boathouse for more boats.

Bamaman, I am new to boating.  Could you please tell me what "porpoise" is?

Thanks
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It's when the bow of the boat is bouncing up and down as your running which means you have too much trim in it.
 
Hehe, don't worry Manitou, you'll know it when you do!! Haha basically it's when you're wide open and the boat's front end starts diving up and down like a dolphin. 

As for hitting 44, I'd say that's pretty successful!  I was getting around that with my 200SHO and 2275RCW with/ESP, just a little over with me and wife and full fuel.
 
Andy, looking for the latest update.  I hope that your boat reaches your expectations but if you only hit 44 rather than 46 I hope that doesn't lessen your enthusiasm.  As you have seen running WOT is too expensive so you wont be doing that too much and your boat will turn heads even when it is doing 18mph. 
 
When a full hull boat like an inboard outboard starts porpoising, you usually would hit the down trim button just a little.  The boat will stop the porpoising and then it'll be at its optimum trim for speed and efficiency.  Pontoons/tritoons are different animals since they're displacement hulls. 

I think my Bennie just starts ventilating a little when going over waves when I trim the motor too high.  I don't remember it porpoising like my old inboard outboards, especially since it's so long.

The whole trick to optimum speed is to get those nosecones up, and it's not going to happen with the engine in the down position.  You've got to trim the engine up to get as much of the hull out of the water as possible.  And at that point with a couple of people and 1/2 tank of fuel you should be getting the redline rpm's out of the motor.  If not, the engine's running too deep or the prop has too much pitch.
 
I think my Bennie just starts ventilating a little when going over waves when I trim the motor too high.  I don't remember it porpoising like my old inboard outboards, especially since it's so long.

Then you aren't going fast enough yet!! Haha
 
Hey Andy, just read through your thread and it sounds like your doing better than me at 44mph. I was only able to hit 43.6 and that was with the trim WAY up. I was porpoising a little when I hit that speed. When I trim down a little I run about 42. One crappy thing I'm starting to notice is that I'm beginning to lose a little speed after 2 months in the water. Last week I went out by myself and was only running 41-42. I examined my toons for algae and noticed a thin white layer of white scale which is really hard to get off. It looks to me to be oxidation. I'm really starting to worry because I got the sharkhide from the factory which is supposed to protect against oxidation. I have been thinking of contacting my dealer about this issue. What do you think? Should this be happening after only a couple of months in freshwater?
 
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Any pics? We keep ours on a lift to keep the crud off. I'll have the boat out this weekend alot and am looking forward to how it does with some weight on it as well.
 
So we had 9 adults in the boat with everyone sitting up front and I was doing 38 and around 57-5800 rpms. I guess that is in line with what others are seeing with a loaded boat. It also still banked pretty good in turns. We then had 4 in the boat and I was back into the 40's. This weekend I raced the sister in laws jet boat and won, I also raced our friends glastron and won as well. I beat them both off the line and stayed ahead.
 
Nice speed and power from a " Toon". I bet their expressions were priceless after getting spanked by a pontoon boat !! :)
 
Sounds like great performance Andy!
 
I just purchased a 24 SLX w/the Yamaha 200XB, the boat is running 42mph on GPS @5,800 rpm with a 14 1/4" x 17M Reliance prop (text book break in with 20hrs on the motor).  I am very pleased and it appears to be consistent with your performance, however, I figure it has more in it.  

What are your thoughts on a lab finished prop? 

2" set back one hole position up?

I feel there is 2-3 mph and more fuel efficiency still in it.
 
Sorry Troy just saw your post. Not sure about a lab finished prop. As for going up a hole I thought of that as well. Should be a pretty easy adjustment. Mine is all the way down and I can't see the cav plate when on plane.
 
lakeliving said:
Sorry Troy just saw your post. Not sure about a lab finished prop. As for going up a hole I thought of that as well. Should be a pretty easy adjustment. Mine is all the way down and I can't see the cav plate when on plane.
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No worries Andy, I will continue to tweak my set up and report back our results.
 
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