Hay guys, I want your opinions. I run a Merc.XR6  150 HP on a Tracker Avalanche with a Tempest stainless 23 P prop. i want more top end, should I prop up to a 24 or 25 pitch? Thanks for looking. I get 60MPH now with a full rig, full gas,2 people weighing 400 total. I'd like to get to 65. I do not have a jack plate as of yet.

The most important thing is what kind of RPM's are you turning with your current prop. I think lower pitch increases RPM's and higher pitch Descreases RPM's.

It would be nice if it was that simple but it's a whole lot more involved than just sticking on a different prop.  

First off, you want to prop it so it's turning the factory recommended rpm with you normal load.  Just changing the pitch of the prop is probably not going to do a thing for top end, other than load the motor down more.  

There is a lot you can do with setup and trying different types of props.  The first and formost item that is essintial in dialing one in is a jack plate.  A 6" hydraulic would make it a whole lot easier but a manual works just fine, you just have to keep adjusting it until you find the sweet spot.   You also need a working water pressure guage to make sure you don't get too high with the motor.  

Different style props make a huge difference in how the boat motor combination run through the water.  Some give huge bow lift, some give bow and stern lift, some give very little bow lift.   This is because different hulls need different things to get optimal performance.

It's all just finding the right amount of setback, the right prop shaft height, and the right prop for your boat/motor combination.  It's a lot of work.

Thanks for your input. Now I turn 5600 to 5800 RPM's. Some times it turns about 6000. Never any higher. I think I will start with the jackplate.

Right now, I would not going any more on the prop pitch, it will probably slow you down, and for sure load the crap out of your motor, and two stroke motors don't like being run loaded down, they live a much longer and happier life being able to spin at near their max recommenced rpm.  Stock, Non DFI motors, I will actually spin 100-200 rpm over max before I would spin one 300 - 400 under at WOT.  It's not hurting the motor, it's just getting above the power band it's ported for so you don't really accomplish anything doing it.

Once you get a jackplate and get your motor up so it's 3" or so below the pad ("the prop shaft" and that's determinded by the prop and hull) will want to try different type's of prop.  Some hulls like a lot of bow lift, some not so much and some need a little stern lift with bow lift.  You will need to hook up with friends that run black motors that might have different props, no way will you want to buy all the different props you might want to try.

When you start getting close on your setup and the speed has increased, you may need to go up one pitch size on the type prop that's giving you the most to get you back down to the recommend max on your motor, but not until then.

Also beware, when you get the hull up and flying like it should be, there is a good chance you're going to find out what the phrase "chine walk" is.

ONE NOTE:  Don't waste you time trying anything aluminum.

So far at WOT its a little loose but still feels stable and it has more to go. Thanks for your help. The jack plate is key for starters. I hate getting beat to the first spot.

If you hate getting beat, go ahead and put you a 260 on it.  

You still may get beat but only by a few.  I can put my 324hp hot rod motor on my Javelin, run 83 mph with two people and gear and still get beat, so don't thing you're not gonna always have one faster.   Granted, when I'm running in the 80's ain't many bass boats gonna come by me but it has happened.  Even had the game wardens staying right behind me one time.  He just wanted to know what I had done to make a boat that big run that d**n fast with a Venom 225 on it, (he was running a Triad with a 225).  Told him it was all in the setup, of course the extra 100 hp from the motor helped.

I have a chance to pick up a stroked 200 with an aluminum fly wheel. The owner claims the motor weighs 300 lbs. My XR6 weighs 416LBS, that would help! There is no replacement for displacement, the bigger the better. My son also drives the boat so I do not want to get too crazy but I would still like to be the fastest to the hole! With your suggestions I can work up to around 65MPH. In my Tracker that's flying! Thanks for the input!!!

When you starting testing props, since you have a Merc you can find a dealer that participates in their try before you buy program. You can try out some different props to see what works with your setup without having to buy one. Good way to find the right prop!

Reliability>Speed

Not exactly true.  My hot rod motor is probably a whole lot more reliable that any stock motor and until I start feeding all 324 of those ponies, it gets a whole lot better fuel mileage than any stock 225 Johnson could ever hope to get.  Cruising at 45 mph, I get five miles per gallon pushing a 20 ft Javelin DC Renegade, that's almost as good as my 225 DFI motor gets.

Properly modified, the motor is a whole lot more efficient, makes a lot more power on the same amount of fuel, and the parts that most commonly break are modified so they don't break.  For instance, a common problem with two stroke motors is the ring locator pins coming out and making the motor go bang.  Mine are top pined and welded so that can't happen.  It's not ported to turn huge rpm's so ring life is just as good as a stock motor.

Now, as for a "Stroked" mercury motor, there ain't no such thing, somebody is feeding somebody else to BS.  Mercury makes a 2.0, a 2.4, a 2.5 and a 3.0 V-6.  Any stroking that can be done to these motors is minimal and that would have to be done by a custom built rotating assembly and know of no one doing that.  More Horse power from a mecury comes from porting, bigger reed cages and front section.  None of this is going to make the motor weigh any less either.

Now, if you XR6 is a 2.5, 150, it can be ported to 300 specs, reeds, intakes and carbs, and front half from a 300 installed and basically have yourself a iron sleeved 300.  All you have to do is turn it 7,500+ rpm's like the 300 and replace the rings every 100 hours or so.

I never saw the 200HP motor but I am a little Leary of the 300lb. weight. How much weight would the 300 mod add to the motor? The boat weight limitation of a 175 hp. motor. 300 might  be a little much but it sounds great!!! What I was thinking was to possible turn the 2.5 liter 150 into a 175 or 200 with mods. What do you think about that? Realistically the 300 mod would be way too much for the boat.

For someone with the tools and skills, it's very easy to make a 2.5, 150, a 225 or anything else you want.   The motor does have to be torn down and when you start getting much over 225 hp, you start cranking up the rpm, that means much shorter ring life.  Then someone with the know how goes in with a die grinder and cleans up all the crap the factory casting leaves behind and change to port heights and sizes to that of a 225.   I don't do mercs but I'm pretty sure the 225 has bigger reed blocks so they have to be changed, which also means changing a lot of other stuff in the front.   Since I'm an OMC guy and can do just about anything with them, I would suggest going here  http://forums.screamandfly.com/forums/forumdisplay.php?f=20.  There are guys on there that can tell you anything you could ever want to know about mercs.    Nothing you do is going to make a noticeable difference in weight.

Don't take this the wrong way but this seams like a lot of useless trouble to gain 5 knots/mph, just so you will not be beat to the honey hole of your and the competitions choice.

Put one of those Yamaha 5.3l 350 motors on that thing and just drive it at 65! Weight, don't worry about the extra weight. If the boat starts to sink at the stern from the heavier motor just go a little faster and before you know it you will at your honey hole and all will be well.

5 Miles and hour. Seams like you would want more after the fiver was added. I would try to increase the speed to at least 100+ that way it will be a while before you feel that need to increase HP to in crease the speed again

Fishing at 65 mph must be a blast with crank baits

Oh If you want to use used what you have and still get to the fishing spot first. Below is all the prop you will need to get their first, It has several settings no tools needed and you can install it your self It can be test either on the lake or at the house on the muffs.  One of the  settings should get you what you are looking for.

If I could chime in. CGH and WTS are both right.

Before you invest in thousands of dollars of motor mods, you really need to think about what you really want out of this boat.

You mentioned that it is rated for a 150, if you exceed the recommended HP, you could break the transom and have liability issues if someone gets hurt.

The 5 - 15 mph (or 50 HP) you will gain will still not be enough because it is never enough. You will get used to the increased speed.

Getting to the "honeyhole" first is over rated. There are always other places to fish. There are always faster boats.

If you are dead set on having the fastest boat, you will have to sell the boat you have and buy a slicker hull with modded 3.0 or larger motor. Might I suggest a 21' allison with a 300?

Sometimes speed compromises fishability and rough water handling.

My old procraft rig does 55 MPH with a 2.0 150 and I am happy with it. I have fished in tourneys that had competitors that had 100+ MPH boats. I beat them again and again at the scales. The reason I won was because I was actually fishing, they were busy driving 100 mph from one end of the lake to the other.

Glades, you are right. My boat can handle 175HP. That is the most I will put on the transom and be safe without liability. i want to get the most from what I have. That will be possible a mod to 175HP. and a jackplate and possibly a different prop. But I like the way Way2slow thinks and I appreciate his knowledge of modifications. If I had the resources to put into a boat it would be very fast but I use what i have and i am not complaining.