24' SXP with 200 hp speed/performance concerns

My understanding is the cavitation plate should be even with the bottom of the center pontoon.  It was the first thing I checked when I picked up the new boat. You should be able to see how that looks on your lift. It will be fairly obvious.  My guess is your mounted to low and that is why they put such a small pitch prop on it to get the RPM up. I think Todd mentioned that in  a previous post. 
 
Actually, I'm pretty sure that the cavitation plate should be even with the top of the water while on plane. I think someone posted a video quite a while back about it. I could be wrong though. 
 
Actually, I'm pretty sure that the cavitation plate should be even with the top of the water while on plane. I think someone posted a video quite a while back about it. I could be wrong though. 

Yes, that is correct. Barely visible on the surface is just about right.
 
Actually, I'm pretty sure that the cavitation plate should be even with the top of the water while on plane. I think someone posted a video quite a while back about it. I could be wrong though. 

Right mine is even with the bottom of the pontoon and when running it is on top of the water. There is also a link showing a guy using  yard stick to check to see if plate is even with bottom of pontoon. I also checked that when I got my new boat. My slippage at 5800 RPM is about 11 percent. 
 
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I have the 6 cylinder Verado Pro I-6 200 hp engine.  I am assuming that changes the numbers and thoughts, but thought I would clarify.

Couldn't find the exact match, but these two are close.  The first is the Mercury Performance Report for the 225 HP version of your engine.  Take a close look at it.  The test boat that they use is "close" but not identical to your boat, but it will get you nicely in the ballpark.  The second is the 250 HP version.  The didn't have a Performance Report for the 200 HP on a Bennington.  YMMV based on a bunch of factors, but that's where you should be starting at IMHO.


The short version is that I believe you should be running at or near these specs:


MAX Performance:  40 mph at 6400 RPM.


Prop: 14" Enertia with 17 or 18 pitch (probably 18).


Ideal cruising RPM: ~4,000 RPM


Report 1: (225 HP) Verado 6-cyl 225 HP on Bennington 2250 RCW


Report 2: (250 HP) Verado 6-cyl 250 HP on Bennington 2250 RCW-ESP.  


Those reports also tell you what mounting hole the engine was using.  Read them as they're very helpful.


Here's a website that does a great job of showing you where the anti-ventilation plate should be, and how to easily measure it.
 
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Right mine is even with the bottom of the pontoon and when running it is on top of the water. There is also a link showing a guy using  yard stick to check to see if plate is even with bottom of pontoon. I also checked that when I got my new boat. My slippage at 5800 RPM is about 11 percent. 

Okay, but being level with with the pontoon isn't the deciding factor.  Where the plate is while on plane is. Maybe level is a good starting point,  but each could be slightly different. 
 
Okay, but being level with with the pontoon isn't the deciding factor.  Where the plate is while on plane is. Maybe level is a good starting point,  but each could be slightly different. 

Okay...we agree it's a great starting point as illustrated by Tcip link.
 
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I am blessed to have access to such a wealth of knowledge, information and help from all of you.  Thanks everyone! :)


Spent this morning with a service guy from our dealer/services center - Spicers up here on Houghton Lake.  The guy was great!  He brought out a 13, 15, and a 17 pitch ss enertia props.  We looked at engine mounting, cavitation plate, and of course propping. We also test drove and played around with engine trim.


When it was all said and done, we moved up to the 15 pitch ss enertia.  Engine mount puts the cavitation plate right at the bottom of my center toon, and just barely noticeable when up on plane. Thus, I think that is precisely where it should be, and it was in that spot all along.


Between the new prop, and adjusting my trim levels, I think we have resolved this issue.  We are now at about 41-42 mph gps at 6000-6100 RPM's with nearly a full tank of gas and us two men on it. The service guy was tall and stocky compared to my somewhat short and trim family. He was like having my wife, daughter, and half of one of my three boys on board with me.  :)


I will play with it some more with different amounts of guests in the upcoming weeks.  However, I am pleased with where my performance is now. I am also very happy about being able to give it much less throttle to get up to 20 and 30 mph.  This will be much better from a fuel consumption perspective.
 
Viking, sounds like you made it home!  Good job...


..and now go back and kick the idiot who said he tested all those props before and said you should have that 11 <banging head against the wall>
 
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I am blessed to have access to such a wealth of knowledge, information and help from all of you.  Thanks everyone! :)


Spent this morning with a service guy from our dealer/services center - Spicers up here on Houghton Lake.  The guy was great!  He brought out a 13, 15, and a 17 pitch ss enertia props.  We looked at engine mounting, cavitation plate, and of course propping. We also test drove and played around with engine trim.


When it was all said and done, we moved up to the 15 pitch ss enertia.  Engine mount puts the cavitation plate right at the bottom of my center toon, and just barely noticeable when up on plane. Thus, I think that is precisely where it should be, and it was in that spot all along.


Between the new prop, and adjusting my trim levels, I think we have resolved this issue.  We are now at about 41-42 mph gps at 6000-6100 RPM's with nearly a full tank of gas and us two men on it. The service guy was tall and stocky compared to my somewhat short and trim family. He was like having my wife, daughter, and half of one of my three boys on board with me.  :)


I will play with it some more with different amounts of guests in the upcoming weeks.  However, I am pleased with where my performance is now. I am also very happy about being able to give it much less throttle to get up to 20 and 30 mph.  This will be much better from a fuel consumption perspective.

Great news Viking! Now that performance expectations have been met you can really love that boat.
 
Great news and have fun!
 
Great news, glad you got it dialed in!  The numbers sound great. 
 
Congrats on getting the correct setup and props to your dealer for the helpfulness.  Now enjoy the hell out of that sweet boat.  
 
I am blessed to have access to such a wealth of knowledge, information and help from all of you.  Thanks everyone! :)


Spent this morning with a service guy from our dealer/services center - Spicers up here on Houghton Lake.  The guy was great!  He brought out a 13, 15, and a 17 pitch ss enertia props.  We looked at engine mounting, cavitation plate, and of course propping. We also test drove and played around with engine trim.


When it was all said and done, we moved up to the 15 pitch ss enertia.  Engine mount puts the cavitation plate right at the bottom of my center toon, and just barely noticeable when up on plane. Thus, I think that is precisely where it should be, and it was in that spot all along.


Between the new prop, and adjusting my trim levels, I think we have resolved this issue.  We are now at about 41-42 mph gps at 6000-6100 RPM's with nearly a full tank of gas and us two men on it. The service guy was tall and stocky compared to my somewhat short and trim family. He was like having my wife, daughter, and half of one of my three boys on board with me.  :)


I will play with it some more with different amounts of guests in the upcoming weeks.  However, I am pleased with where my performance is now. I am also very happy about being able to give it much less throttle to get up to 20 and 30 mph.  This will be much better from a fuel consumption perspective.

Over 40mph...... life is good!! :)  
 
...and now go back and kick the idiot who said he tested all those props before and said you should have that 11 <banging head against the wall>

As wonderful as my service tech was - he was - it was the same guy. He was very skeptical when he first got here yesterday.


He started out politely with "the current prop should be the way to go...who have I been talking too...what boat and engines do they have because numbers don't translate...we work hard to get this right for people the first time...etc..." 


That said, he was polite and patient with going through our tests, full of helpful advice and observations, and we eventually got it dialed in. He didn't blow off the process, have an attitude, or skip or overlook anything I was asking about.


When we were all set, he was on board with the necessity of the change we made.
 
As wonderful as my service tech was - he was - it was the same guy. He was very skeptical when he first got here yesterday.


He started out politely with "the current prop should be the way to go...who have I been talking too...what boat and engines do they have because numbers don't translate...we work hard to get this right for people the first time...etc..." 


That said, he was polite and patient with going through our tests, full of helpful advice and observations, and we eventually got it dialed in. He didn't blow off the process, have an attitude, or skip or overlook anything I was asking about.


When we were all set, he was on board with the necessity of the change we made.

The good news is that you got a great lesson on propellers, performance testing, pitch, mounting holes - and "crowdsourcing" of information.  Enjoy the boat!  Being up in Michigan I imagine you've only got a couple of weeks until winter sets in again!  :D
 
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