Top end?

How many rpm's are you running.  i am assuming that you rocket out of the hole.  If the previous owner was getting 55 he was way over reving the motor with a 19 pitch prop.  For 50 mph you will need a 21 or 23 pitch prop and enought ponies to turn it. 

This might help.  A pretty good prop/speed/slip calculator.

www.rbbi.com/folders/prop/propcalc.htm

with that boat and motor, I'd bet big money that is the max your going to get without a jackplate.  that's a pretty heavy boat with alot of hull in the water. 

Pro V1 Said:
I recently purchased a new rig (new to me) and have been a bit disappointed with the top end I'm getting out of it.  It is a 1997 Alumacraft trophy 190 with a 175hp Evinrude intruder 2-stroke.  It has a 19 pitch evinrude stainless steel prop.  I have only gotten 46mph (GPS) out of it so far but figured I would get at least 50?  The previous owner claimed to get 55 out of it but I'm assuming thats with the paddle wheel style speedometer and we all know how accurate those are?  Any thoughts?

Appreciate the comments fellas.  Had four (fat guys) in the boat today so it wasn't a good day to play around and sportfish yeah it is a rocket out of the hole.  Plan on goin out solo this weekend so I'll be able to play around a little more.  Thanks again guys.

What RPM's are you pulling at wide open throttle, fully trimmed with just you in the boat?  That would really help determine if your propped correctly. 

Pro V1 Said:
Appreciate the comments fellas.  Had four (fat guys) in the boat today so it wasn't a good day to play around and sportfish yeah it is a rocket out of the hole.  Plan on goin out solo this weekend so I'll be able to play around a little more.  Thanks again guys.

What should a guy be topping out on RPM's fully trimmed I get about 5100 is that to much for a optimax?????

eyexer, I'll let you know come friday.  I've only had the boat a week so I haven't had much time to goof around by myself.

Goose, sounds like the rubber washer in your hub is stripped out.

Horsager Said:
Goose, sounds like the rubber washer in your hub is stripped out.

Either that or he may want to pull in the anchor! 

Seriously, that sounds to be a pretty good guess but I would think it would deteriorate rapidly once it started to slip and one would have a free spinner soon.

Sure sounds like Goose spun his hub or if he has a ported prop with the plugs installed maybe the plugs have come out.

Rooster, I'm not sure what size Opti you have but my 225 reccomended RPM limit is 5750. I can assure you that running 5100 rpms your not getting everthing out of that motor and you're at the bottom of the reccomended operating range. I would go down a couple of degrees in pitch and shoot for about 5500 rpms.

Pro V1, If it were my rig I would get a base line on speed and the rpms at WOT. Although you're running a SS prop it would be nice to know which one. Is it a raker or a cyclone or something different. If it's a raker it sure sound like it's not running to it's potential. If you have access to a compression gauge it probably wouldn't hurt to check the compression on each cylinder. if that checks out then we can work on finding the right prop.

I've been though five differnt Mercery Stainless Steel props and can speak from experience that having the right prop makes a world of difference.  Every prop I tried ran correctly in the appropriate rpm range between 5400 and 5700 and ranged from 21P to 23P. I tried 3 differnt 3 blade props (Enertia, Tempest Plus, & Vengence), the four blade Trophy Plus, and the five blade High Five. I was able to see a 5 mph speed difference from the slowest to the fastest prop and the hole shot was different for every one of them. I end up settling on using a 21P Tempest plus as my primary prop and kept the High Five as a backup. I have one last prop I would like to try which is the Rev4, which is basically a 4 Blade Tempest. I just haven't run accross a cheap one yet.

That top end sounds about right.   I guarentee you that boat has never touched 50 mph, let alone 55 mph.  Trophy's are deeper, heavier boats that aren't designed for speed. Good boats, just not fast.   My friend owns a Tournament Sport 185 alumacraft with a 175 yamaha hpdi on it.  This boat is a little more streamlined than yours, and this boat gets 46-48 mph if everything is just right. I have seen 50 on it going downstream wiht the current.    Considering this, your 46mph seems about right.  

YarcraftStorm Said:
Sure sounds like Goose spun his hub or if he has a ported prop with the plugs installed maybe the plugs have come out.

Once your up on plane there should be enough water pressure to keep the exhaust inside the prop until it vents out the back.  Generally the only trouble you'll have with the vents coming out is the prop blowing out when you're trying to get on plane.

Horsager, this is true on "MOST" props. However I have found on the Trophy Plus, that even with a prop ring, for what ever reason this prop will also vent at fast speeds. Unless I was over 3/4 throttle and over 45mph the trophy was doing a burnout when the PVS plugs were out.

I believe they should run 5500-6000 if my memory serves me correctly. 

rooster77 Said:
What should a guy be topping out on RPM's fully trimmed I get about 5100 is that to much for a optimax?????

I have a ported prop and checked the plugs, they are all still installed.  I will have more detail after I pull it apart tonight.

Pro V,

Buddy has the same boat but with a 175 Yamaha, he has no problem throwing around a 21 P prop. Dont know for sure his top speed as he typically runs 75% throttle.

http://www.mercurymarine.com/engines/outboards/optimax/index.php

Rooster, I would look at the above website and see if you can find a matching performance test for your motor.  Not all Mercs have the same recommended WOT rpm.

p.s.  Most engine manufacturers have their performance tests online.  Good reference point to start with for prop selection, fuel economy, and recommended operating ranges.

Everyone thanks for the great posts its awesome to get info from guys that use and know there equipment Awesome Thanks Everyone!!!!

This topic got me questioning what I am getting from my boat. I have a alumacraft trophy 185 with a 130 honda on it and I get around 38 mph tops. Does that sound about right? I thought it should at least hit 40-42. Maybe I am just hoping it is supposed to go faster. The only real weight on the boat is a kicker motor. By the way, the pitch is 19 i believe. Any thoughts? Thanks.