1998 bass tracker pro 175 with merc 90hp

[cozzmo1970]

i have a 1998 bass tracker pro 175 with 90hp merc. it has a 21p aluminum prop that came on the motor when i bought the boat last year. It currently gps at 42 the rpms between 5300 and 5400 maybe 5500. i would like a little more speed if possible i know its just a bass tracker but i'm sure it can do better. my question is what is the maximum pitch and how many blades should i choose.i do pull a tube for the kids and dont have to worry about rough waters

 

[kmarine]

you are at the point where experimenting with the prop by trial and error is necessary. A good prop shop could not only check pitch, but adjust the cup as well. I don't know where you live so it is difficult to recommend a prop shop. Airmarine in Chicago has a demo prop program. They have rebuilt and specified props for me for decades. I recommend a sst prop for max speed.

 

[alldodge]

i have a 1998 bass tracker pro 175 with 90hp merc. it has a 21p aluminum prop that came on the motor when i bought the boat last year. It currently gps at 42 the rpms between 5300 and 5400 maybe 5500. i would like a little more speed if possible i know its just a bass tracker but i'm sure it can do better. my question is what is the maximum pitch and how many blades should i choose.i do pull a tube for the kids and dont have to worry about rough waters

Agree with kmarine and will add, don't go with more blades since it is used to do other things then going fast. While more blades (4 and 5) will give you more lift, that lift will reduce your ability to pull a load. I would suggest going to a place which sells props and allows you to try some out. My first thought is to go from aluminum to stainless because while the prop is heaver, stainless will not flex as much under load. Now you are talking about WOT and not over all performance

 

[cozzmo1970]

thanks, over all performance is best for me i just thought with a 90 hp this small of a boat would be faster the guy i bought the boat from put the 90hp on him self so im not sure if its even set up for best performance. the motor is set down to the second lowest holes possible. i live in south georgia and no one here allows prop swaps. the selector on the mercury site says use a ss 21 i just dont want to pay $400 and should have got a 22p.

 

[Texasmark]

You are doing just fine as you are. Leave it be. One of your negatives is your comment about water toys. You can't max speed and tolerate water toys, just isn't the way it works unless you like to swap props every time you decide to do something different.

I just spent half a dozen years with an alum boat the same size as yours with the same engine. Difference in mine and yours is that I didn't tow water toys and my bottom was stepped, like a fiberglass pad boat whereas as you would increase speed fewer of the steps got wet meaning that less hull was in the water and there was less drag allowing for a higher pitched prop and more mph. Look at the wake in my Avatar and look at your wake at WOT. That's the difference a stepped hull makes.

Best I could do with a Ballistic 13+ x 24XL SS high performance prop was 48.5 gps with me alone in the boat (see my avatar) at 5800 rpms. I had to port (drill vent holes) in the prop to get a good hole shot with this much pitch.

My best all around prop was a Ballistic 13+x21 SS which I could get up to 45 but I was running up around 6000 rpm and I could add a second person to the boat and it didn't make much difference. But I didn't like running that high and if I didn't look at my speedometer which was reading about 1.5 mph too high at WOT I didn't know the difference between 40 and 50 mph.

So, my man, been there done that. Now if you just want to puke your money, I gave you a couple of data points that will be above, but close to, where you should get.

HTH,
Mark