Leave well enough alone or make a change?

[CincyGus]

Hi All!

Just found this forum recently and this is my first post. I recently bought a 2020 Tracker Pro Team 175 TXW w/ 60hp Mercury on it. After researching a little I've discovered that it has a 10 3/8", 14 Pitch Black Max Prop (816706A45 stamped on the prop).

A buddy of mine that I've fished with out of his 17' aluminum boat (similar size) for the past 25 years mentioned that my prop is very small to what he is used to seeing. He has a 90hp Mercury as his is a deep V aluminum boat vs. my modified V.

The boat has been out about 8 times since I've bought it, has completed the break-in period and here are some thoughts/numbers after testing it out. Fully loaded with rods, tackle, all safety gear and a full tank of gas (21 gallons) she planes out pretty quickly (5-6 seconds) and after tapping the trim a bit I can max out at about 5500 RPM's and 34.2 MPH by myself. With a second person in the boat, she does about 32 MPH still at 5500 rpms.

I plan on using her about 50% of the time for fishing with one other person and the other 50% of the time pleasure boating with 3-4 people total in the boat and occasionally pulling a tube.

Is there any benefit to going with a bigger diameter prop in the same or a different pitch? I'm pretty pleased already with the performance with just 2 people in her but don't want to leave any performance improvements once I lad her with 3 more people besides me as if the MPH drop from adding one is relative, She will likely slow to about 27-28 mph then.

I've attached two pics. One is a sticker of the lower unit and I'm not sure what the numbers represent if someone could explain that to me. I'm guessing max prop size and gear ratio and something else (max pitch?) but those are all three guesses.

thanks in advance for any info or direction.

 

[ThomW]

You are correct the numbers are the largest diameter and pitch that can fit on motor, the other number is the gear ratio for lower unit.

Changing pitch will affect your WOT RPM's. Generally speaking each inch you drop pitch raises RPM's at WOT by about 200. Each inch you increase pitch will drop RPM's by 200.

The diameter of prop basically deals with the load the prop can handle and push. Larger boats with heavier loads need larger diameter props. Increasing diameter will actually lower RPM's, and decreasing diameter will increase RPM's. Perhaps a larger diameter would help the prop push more weight, but I don't know that your performance would improve.

If you are getting 5500 RPM's and 32 MPH with 2 people, you are doing okay with a 60hp. I wouldn't want to raise your max RPM's much more than that, depending what specs are for that motor. IMO, I'd probably leave it alone.

 

[gm280]

To start with, are those MPH numbers via an in-dash speedometer or true GPS readings? Most speedometers in dash using a pitot tube are really not very accurate. So I would find a GPS setup either on your phone or such to make any comparisons. But obviously we all want to go fast with amazing fuel economy. But it just doesn't work that way most of the time. Unless you are traveling on the water for hours on end, your arrival times to most any place on the water will be less then minutes apart for any increase of speed. I'd be happy and boat on. Trying to tweek a boat setup for the absolute best speed possible usually costs a heck of a lot of dollars for so little increase, if any. JMHO

 

[WesNewell]

The Numbers on the sticker are both the gear ratio, just in different forms. The 12x22 is the actual number of gears 12x 22. Nothing to do with the prop. Divide 22 by 12 and ou will come up the the GR of 1.83:1. Just 2 forms of the same thing. And you sure as heck wouldn't use a 22" pitch on it unless you had a boat that only weighed a couple hundred lbs. Largest pitch I found that fits is 17P and you don't want to go higher in pitch anyway. If anything you may want to go to a13P with a full load. The numbers on the side of the prop are probably the prop part number. I didn't look it up.

 

[WesNewell]

I should have added something about engine mount height. That boat has a 22.25" transom so it 's probably ok, but I've seen many mounted too low causing more drag and a lack of performance. With the av plate in line with the hull bottom, you do not want it below the hull.

 

[CincyGus]

GM280,
Those were GPS MPH from my Lowrance fish finder. And I'm fine with the speed I have now with two people in the boat. I'm not a 50 mph+ guy anyway, makes me too damn nervous, especially in something fairly flat bottomed that can catch a lot of air. They way it runs with just two for fishing is perfect for me.

I'm only asking if there is something I should change for the times I'm pulling a tube of more heavily loaded with 3 passengers and myself.

Wes, Thanks for the clarification and I will check the mount height. I had picked up on some other posts while I was reading everything I could about performance prior to my post but have not checked mine yet. Understand they often come setup incorrectly and below the hull. Thanks for the reminder to check ;-)

Appreciate everyone help!

 

[CincyGus]

Wes,

Guess I was fortunate as my motor is mounted perfectly (Top Spot) and the AV plate is even with the bottom of the boat.

 

[Texasmark]

Leave it be. 60 hp isn't 90. I ran a 90 on such a boat as your buddy. You are doing about all that 60 can do which is a nice clip, nothing to be ashamed of. If you want to spend some money and have something to "diddle with" then go ahead and play around. Don't be surprised if you wind up back with what you currently have with your pockets a little lighter for the experience. Wink!

 

[CincyGus]

Just an update:

I did get out on the lake with 3 others and pulling a tube. One @ 180 lbs, one at 130 lbs and one at 150 lbs, besides myself for some tubing. Top speed I could get with everyone in the boat was about 25 mph. With one on the tube, about 21-22 mph and when I would make a turn, it would drop to between 15-13, depending on how tight of a turn. A contributor to that low speed I believe was the rope hanging in the wake. I purchased a tow rope with a booster ball to help address that problem and am going out with just two people tomorrow, approximately 330 lbs+ me (vs. the previous 460+me). I'm hopeful that I can maintain 18-20 mph in the turns and get people outside the wake much easier which was very difficult on the previous trip with the rope/wake issue.

I'll update the post after my trip tomorrow with new performance feedback in case someone in a similar situation is fighting the same issues. I believe between the booster ball, one less person in the boat/weight reduction, I should be right there where I need to be to have some fun tubing.

 

[WesNewell]

You will probably want a 12P prop when going loaded and pulling tubes. I run a 14P on my lowe stinger 175, but never with more than 2 people and never pulling anything. My top speed is ~38 mph alone, 35 mph with 2 people. From the factory it was 31 mph with a 12p prop. Only got 35 mph with 14p prop until I raised the engine as high as it would go, another 1.5", and gained another 3 mph.

 

[CincyGus]

Wes, Is that with a 60 hp?

Okay, Some feedback from today. 3 people in the boat, about 25 lbs under the 555 lb limit. Also added a tow ball which helped dramatically. Pulling the heavier of the two folks (200 lbs) and with 2 people at 330 lbs total in the boat, I was able to get up decently fast and a top speed of 27 mph (GPS) @ 5400 rpm.

Dramatic difference and very acceptable performance for tubing.

Top speed today when we were just cruising was 31.1 mph with 3 people (glass lake conditions and 3/4 tank of fuel). significantly smaller and under the limit vs. the previous post with 4 people and slightly over the passenger weight limit.

Here's some thoughts.

I still have never gotten my RPM above 5600-5700, even when only myself in the boat. I the only way I think I would ever hit the 6000 top RPM is if the boat were completely stripped of everything and I'm by myself. Which that will never happen. I will always have some gear and almost always (80% of the time) at least a second person. Today and generally, top RPM at WOT is between 5400-5600 based on passenger # and gear loaded.

I'm thinking go 1" bigger on the prop. and down 1" in pitch to a 13. Should keep my RPM's about the same as one drops RPM and one raises, counteracting each other to some degree although maybe not perfectly.

Thoughts or comments?

 

[WesNewell]

Yes. 2017 60 hp 4s. Boat dry weight is 995#. If you want 6k rpm, you'll probably have to go to a 12P prop. That's what I got with my original 12p prop. Get about 5500 with the 14P. At 55-5700 rpm now, you're at a good rpm.A 13P prop would probably be a good all around prop for you.

 

[CincyGus]

UPDATING******************************

I went and got a new SPITFIRE 10.1" x 14P (8M8026635) after internally debating all the info I have learned above, reading other threads, reading reviews on Amazon on different props that had them installed on the same boat and watching everything I could on prop changes on my Merc 60/175 txw combo.

Finally got it installed and out on the water this weekend and couldn't be more happy. Had a significantly quicker on plane time and actually got up to 5900 RPMs (+200 From the highest it had ever been with the stock 10.3x14P Black Max 3 blade) and with another guy in the boat with me on a pretty good chop, I managed to hit 33.2 which is + 1mph better than I had ever done with 2 people in the boat on glass water. I believe she will do 34+mph on glass w/ 2 people and 35+mph by myself on perfect water.

I also noticed I could trim up engine up farther than I could previously without it porpoising and the spray from the boat has moved about 5"-6" farther back than it was previously with the same load. So I believe I am getting more hull out of the water and that's what's giving me better speed. No issues with cavitation on tight turns or any other time.

I was been willing to sacrifice a little top speed for a better hole shot and quicker acceleration but looks like I hit the magic combination for this boat and engine as I didn't give up anything but rather had everything improve.

Hope this thread helps someone else with this combo. I highly endorse the Spitfire (see model# above) for this engine/boat combination.

Thanks for everyone's comments and help in getting me here.

P.S.

Just noticed I never updated after post #9. Highly endorse the booster ball also. It helped get the rope out of the water and helped speed I could keep the boat at while tubing significantly.

 

[Texasmark]

It's not rocket science that you reported what you did. I had a look at the prop on the Amazon www and it clearly stated that the 4 blade had more area for hole shot, was cupped which helped you to hold in turns and high trim angles and not ventilate, and had a good rake which causes, as you noticed and properly commented, lifting of the the bow which reduced the wetted area of the hull, reducing drag, and giving you more from what you have for a propulsion source. Good Selection!

You probably will get yourself into porpoising situations when you change speeds. Cure is either tuck the trim in till it quits, or if you have the ponies, accelerate till it stops. Slower speeds require less trim for stability.

 

[CincyGus]

Appreciate the comments and tips Texasmark. For me, being a new boat owner, even though I've fished out of the back of one for 30 years +, trying to take in all the info I could and make a decision sure felt like rocket science or Chinese Arithmetic , lol. Just have to get used to it a bit more as the only porpoising I saw this past weekend was when I was pushing to see how fast she would go (WOT) and trimming up much farther than I had been able to do with the previous prop. A quick tap back downward on the trim and she settled right in. Call it an educated guess after all the research and advise I got both from this and opinions I snagged from many other threads and Youtube videos but I feel like I hit the bullseye on getting the best performance I can on this little 60hp Mercury/boat combination. If there's a better prop out there for this engine boat combo, I can't think it could be better by much.

 

[Texasmark]

" I feel like I hit the bullseye on getting the best performance I can on this little 60hp Mercury...."

I totally agree and you surpassed my expectations of how well you could do.

 

[QBhoy]

My prop slip ocd is off the scale with this post, haha. Enjoyed the read though.