Larger motor, how much gain in MPH?

[livemusic]

I have a 17' 1997 Bass Tracker with 40hp Tracker (Mercury) motor and with me, alone, it will go 29mph. Still considering buying a new boat. If I were to get a similar size boat and put a 60hp 4-stroke on there (Suzuki, Honda, Yamaha), any guess at what top speed would be? What about 70hp? 90hp? What if I buy an 18' boat? I know this is impossible to answer correctly, just wishing I had an idea.

If a manufacturer builds a boat for me, do you think they can give me an accurate prediction of top speed or is that something that has to be measured after it's built?

[iabass8]

impossible to say. too many variables. construction (glass/tin). prop pitch, prop blades, hull design, how much weight in boat, jackplate.

Same goes for 18' boat. 90hp on an 18' tin is fine. 90hp on an 18' glass would be miserabble.

If you buy a boat stock from a manufacturer they can give you a good estimate of top end speed range within 3-5 mph.

If you know specific boat/motor, you could get a better answer. Simlly asking for top end on an 18' boat /w a 90hp motor will get 11 different answers from 11 people.

[livemusic]

26 minutes ago, iabass8 said:

...If you know specific boat/motor, you could get a better answer. Simlly asking for top end on an 18' boat /w a 90hp motor will get 11 different answers from 11 people.

Yeah, I know it isn't possible to pin it down, I said that. Just wondering if a general broad guess is possible, such as "A modern aluminum boat should do 35mph or more with a 60hp motor."  Something like that. Or if, say, a 5mph range is possible, i.e., 35-40 mph or 40-45 mph.

BTW, I was talking about an aluminum boat.

If I had my druthers, I'd like to get one that'll do 40-50mph. In fact, 40-45mph might be fast enough, I am no speed demon but sometimes I'd rather go faster than 29mph, lol.

[CarolinaBoy4Life]

Not sure what its worth to you but I have an 18ft center console bay boat with a 70HP Johnson and it will top out at around 43 MPH with just me in it and gear. With two people its more around 38MPH. Plenty fast enough for me at the moment. Boat style, engine size, load etc. would vary MPH that are able to be achieved.

[fishnkamp]

First, if you are unsure what you want, think it through this way. You seem to be really unsure of what is most important to you in a boat.  Never go smaller for speed you will regret it. Pick the type of boat first, ( aluminum, fiberglass, tiller, side console, dual console), based on the waters you fish. Are you fishing small creeks and rivers, small to mid size lakes or big rough water lakes and tidal waters?  Now look at those choices and determine what  size is safe to run there and last how much horse power is needed to make it perform properly.  If your boat is safe and has enough deck space now, then almost any new boat in similar size will have a wider hull, more storage and perform better than what you have now.  If you are interested in another aluminum boat there are a bunch of really good ones including the new Trackers. If you looked your boat it is 17 feet long with a 71 inch beam with a 60 hp max.  A new Bass Tracker Pro Team 175 TXW is 17 feet 7 inches long with a beam of 89 and has a max rating of 75 hp.  If you choose a 50 hp 4 stroke they estimate top speed will be 34mph, a 60 is estimated to go max 37 and with a 75 hp 4 stroke they advertise a top speed of 40 to 41 mph.  Now that is a much bigger boat, it is 7 inches longer but 18 inches wider and the beam is carried much further forward than on your boat.  It is expected to go anywhere from 5 to a max of 12 mph faster, carrying a much more comfortable sized hull. These numbers are found directly on the Tracker website. Go to their website, drop down the mod Vee tab, choose 2017 models, then Pro Team 175 TXW. Next look under "Motors" tab. Now I am not saying to get a better performing boat you should go out and buy a new one ,there are lots of these "newer boats" (that is compared to your) that may be only a few years old and available for sale used at a decent saving. This is no knock on the boat but rather a statement showing lots of anglers buy this popular boat and then in a few years decide to sell it and move into a large fiberglass bass boat. I am not trying o talk you out of the excitement of ordering a new boat either. If you do you can choose higher end electronics and some other goodies.  One other thing is that even though these newer boats with bigger engines go faster the fuel they consume may be not much different than yours does now.

If you consider a Tracker Pro Team 190 that is a boat measuring !8 feet 7 inches with a beam of 89 inches. Its max hp is a 115 four stroke and it runs an advertised speed of 46 mph.  Now that is hauling a much bigger hull with bigger decks, storage and seating room than yours.  I am not even suggesting to go with a Tracker I am just comparing what they make now compared to back in 97. Take a serious look at Tracker, Triton, Ranger, Lowe, Xpress, Alumacraft, Polar Kraft, Lund, G3 nd I have probably forgotten somebody's toys.

[fishnkamp]

Boy there is no problem finding a bunch of boats to look at in you state.  Check out these as examples. Now I have no idea where these are compared to you, within your state but they are good examples of boats being sold in your state. I found them just with a couple of minutes of searching Craigslist Louisiana.   check these out.  http://batonrouge.craigslist.org/bod/5678004325.html

http://batonrouge.craigslist.org/bod/5703590884.html  http://batonrouge.craigslist.org/boa/5699611167.html   http://batonrouge.craigslist.org/boa/5666031544.html

[gim]

Just as a reference, I have a 2015 Ranger RT178 with a 75 4-stroke merc and I get about 35 mph out of it with another angler, gear, bow mount, factory aluminum prop, and talon on it.  They advertised 40-41 mph but there are so many variables that go into it you may not know until you try it.

[Goldstar225]

fishnkamp really covered it well for you.  For some reason Ranger tends to rate their aluminum boat speeds slightly lower than tracker does for the same or similar sized boats/motors.  Maybe it's the hull design or weight of the package.  One thing I've noticed, it takes a LOT more horsepower to make a substantial difference in the speeds produced.

[fishnkamp]

I have owned 11 boats over 40 years and I have changed my craft when I changed the water I fished mostly. I owned a tiny 12 ft jon to fish an electric only reservoir, 2 different canoes for fishing small rivers, a 15 ft tiller control 9.9 powered jon for fishing The Susquehanna River. The a !7 foot aluminum with one of the first jet powered outboards in the state of PA (before the factories sold them as a package.) Then finally some bigger Fiberglass missiles  The big one was 20 foot with a 200, what an amazing 75 mph rocketship.  And now  I am back to fishing from aluminum. It is a very comfortable 17.6 ft 85 inch beam Lowe stinger 170 with a 2 stroke 75 hp merc. With some fine tuning, the install of a Sting Ray hydrofoil, and a complete custom rework of a prop I   get a smooth quick hole shot with very little bow rise and a top speed of 33 mph. I think I could have added a bit more cup and gotten 37mph if I did not run the Sting Ray.  I choose to give up the extra speed in exchange for better rough water handling, see I now fish on the Tidal Chesapeake Bay tributaries and the Potomac River. If you watched the BASS Elite Series tournament last year from the Chesapeake Bay you will remember the competitors complaining about the rough tidal waters. Any time the wind blows from one direction and the tide runs the other you will get 1 to 3 footers and a rough ride. Of course the tide changes every 6 hours and 20 minutes.  Anyway, that is a long way of explaining what I mean about choosing your boat based on the requirements needed to be met in order to safely fish your chosen waters.  In some cases we owned more than one of our boats at a time. Here is a pic with the old 25 hp engine that was setup special to fish a hp restricted lake. We fished it for 4 years before selling off the engine and trim/ tilt plate and repowering with it's current 75 hp Merc. She did 18 with the 25 hp.  Same boat setup totally different for different needs.

[A-Jay]

 Liking the 18' "Tin" boat.

Has a 96" beam ~ handles sloppy conditions well.

Cruises comfortably

A-Jay

[S. Sass]

As everyone stated all boats vary but for a reference my 18' Aluminum 2000 SeaArk with the 115hp 2 stroke Johnson carrying 2 men and a a lot of tackle will do 49mph on a GPS   

This is a 18' boat with a 7' beam and a dry weight of 1315 lbs. 

The only modification to it that I am aware of is the 13 1/2 X 21 Stainless Prop. 

[S Hovanec]

My 17' Lund with 135 Honda tops out at 45-46 with just me in it and 42-43 with me, the wife and both dogs.

[Further North]

There are a lot of boat tests published in the Internet that'll get you in the ball park.

Another reference point: 2005 Crestliner CMV 1850, Suzuki DF 140.  44 MPH with just me an a full load of gear.  It's got a 96" beam as well, IIRC.

It ran 48-49 MPH without all my "stuff".

[Effie4Bass]

My two cents worth.......The end all be all boils down to this.  The only function of the boat is to keep the water out; however, the function of the engine is not only to get you there but to bring you back home!!!  I've always bought what I thought I could afford with the possibility of a re-power in the near future.  So I spend a little less on the boat and usually get a better engne.

My current boat is a 2002 PolarKraft bass boat I found last fall. This spring I repowered with a Yammy 90 4 stroke.  The boat is rated for a 150 hp but the wallet couldn't stand that big of a hit.  I'm getting 34 mph (gps) and that is fast enough to put bugs in my teeth.  Also fast enough to get me to where I want to be. I know it will get me back and it has a 6 year warrantee.  Now if i could just stop hitting rocks just under the surface I'd be all right.  Our lakes in Maine have stayed very shallow this past summer.

[Further North]

On 8/10/2016 at 11:54 AM, iabass8 said:

Same goes for 18' boat. 90hp on an 18' tin is fine.

I have a 140 on my 18' tin boat...it is rated for 150.

[Way2slow]

Actually, it's very simple when you size a motor for a boat and speed is a concern.  Install the max HP two stroke motor the boat is rated for with the proper size and type SS prop on a properly sized jackplate and you can get all the speed the boat you like has to give.   If finances don't allow all that, leave off the jackplate, SS prop and down size the motor to no less than 25% smaller than the rated HP.  Anytime you go more than 25% smaller than the rated HP and speed is of any concern. you will probably never be happy with that boat.  Under powered and speed are not two words that go together on a boat.

Now, if speed is a key point in picking out a boat, stick with the hydro rockets like Bullets, Allison's, Gambler, Stroker etc. 

However you should also realize, the desire for speed can make owning a boat very expensive and the faster the hull design, the more and more expensive it gets because you are constantly making changes that might add another MPH.

Also, one must understand, speed should not be the main reason for installing a max rated HP motor on a boat.  Just because you increase the HP on some hulls, does not mean you will see big gains in speed also, some hulls hit a wall at a certain speed and doubling the HP only produces a small gain in speed.  You want the Max HP for load carrying ability and getting on plane with a load in it.  Small motors can make a miserable trip when the boat has a load in it and trying to get on plane.   It's a lot of fun having to tell some one they need to get up and go to the bow, just so you can get the boat out of the hole, or making sure all your gear is as far forward as you can get it.

[WRB]

On August 10, 2016 at 9:35 AM, livemusic said:

I have a 17' 1997 Bass Tracker with 40hp Tracker (Mercury) motor and with me, alone, it will go 29mph. Still considering buying a new boat. If I were to get a similar size boat and put a 60hp 4-stroke on there (Suzuki, Honda, Yamaha), any guess at what top speed would be? What about 70hp? 90hp? What if I buy an 18' boat? I know this is impossible to answer correctly, just wishing I had an idea.

If a manufacturer builds a boat for me, do you think they can give me an accurate prediction of top speed or is that something that has to be measured after it's built?

On the transum there is a plate that states max HP rating, don't exceed that if you want your insurance to be in affect.

Quick search without know your model 40 HP is the max rating for nearly all 17', 1997 Bass Trackers.

Tom 

[A-Jay]

On ‎11‎/‎4‎/‎2016 at 7:52 AM, Way2slow said:

Actually, it's very simple when you size a motor for a boat and speed is a concern.  Install the max HP two stroke motor the boat is rated for with the proper size and type SS prop on a properly sized jackplate and you can get all the speed the boat you like has to give.   If finances don't allow all that, leave off the jackplate, SS prop and down size the motor to no less than 25% smaller than the rated HP.  Anytime you go more than 25% smaller than the rated HP and speed is of any concern. you will probably never be happy with that boat.  Under powered and speed are not two words that go together on a boat.

Now, if speed is a key point in picking out a boat, stick with the hydro rockets like Bullets, Allison's, Gambler, Stroker etc. 

However you should also realize, the desire for speed can make owning a boat very expensive and the faster the hull design, the more and more expensive it gets because you are constantly making changes that might add another MPH.

Also, one must understand, speed should not be the main reason for installing a max rated HP motor on a boat.  Just because you increase the HP on some hulls, does not mean you will see big gains in speed also, some hulls hit a wall at a certain speed and doubling the HP only produces a small gain in speed.  You want the Max HP for load carrying ability and getting on plane with a load in it.  Small motors can make a miserable trip when the boat has a load in it and trying to get on plane.   It's a lot of fun having to tell some one they need to get up and go to the bow, just so you can get the boat out of the hole, or making sure all your gear is as far forward as you can get it.

Absolute Agreement.

A-Jay