1989 Bass Tracker porpoising

[bcj.jones]

Firstly thanks for any help y'all may have. I have a 1989 Bass Tracker Tx-17 with a 60 horse evinrude. Plenty of power for the boat, planes out in a second but I can no trim up at all without it porposing. I get about 33 mph with just me, normal fishing gear, 12 gallons of fuel and two batteries. I feel like i could get another 3-5 mph if I could trim up at all. I feel like I'm running with 3/4 of the boat in the water. Plus, with the bow of the boat held down to the water so hard, I feel like it would handle differently if I could get it to trim up some. It has a 17 degree prop on it. Runs right within the rpm range at W.O.T. I've heard adding a "whale tail" on it helps but I don't understand how? Any opinions?

 

[alldodge]

can no trim up at all without it porpoising

Your probably right where you need to be with how the boat is currently loaded. Porpoising is caused by to much trim as you know, but since you cannot add any, then you may need to move some weight forward,

Is the Cav plate even or tad above the bottom of the hull? Maybe a pic?

 

[Scott Danforth]

No, dont add a tail.

Move some weight like the cooler of beer up towards the bow

 

[WIMUSKY]

Yup, tail heavy..... It would handle much better if you can get the nose up..... I bet the wheel is very stiff right now while underway....

Like AllDodge mentioned, a pic from the side at the transom would help too. Kneel down so we can compare the cav plate to the hull, may need to raise the motor. Your issue could be a combo of a couple things.... Raising the motor will add some rpms which is fine if you're not at the very top end of your WOT range....

But, I would bet you're just tail heavy...

 

[scoflaw]

Raise your motor 2 holes, worked for me. With your boat on plane your cav plate should be visible.

 

[Watermann]

The issue you're describing is confusing to me as you say that 3/4 of the boat seems to be in the water and if you trim out the boat porpoises. Being stern heavy usually causes porpoising not having 3/4 of the boat plowing in the water with the bow being held down like you're describing.

I found a pic online of what your boat hull looks like. Does it have a forward livewell in the front casting deck? All the normal stern heavy remedies like a whale tail thing will only push more of the bow down. Take a peek underneath the boat and see if there is any damage like a dent toward the stern.

 

[bcj.jones]

Yea, I think the motor needs to go up a hole..maybe two?

 

[Watermann]

It's difficult to tell from the pic how high the AV plate is in relation to the bottom. With the motor trimmed all the way in, use a straight edge of a 2x4 flush against the bottom measure the distance from where the AV plate is in relation to the 2x4.

 

[jbcurt00]

Almost looks too high in that pix

perspective?

 

[bcj.jones]

Sorry for my ignorance but the cavitation plate is the plate right above the prop correct? Not the second one above the prop?

If I'm correct on that then here is another pic. It measured at 5/8ths of an inch below the bottom of the boat. I measured the holes a well, and the measure right about 5/8ths of an inch apart from center of hole to center of hole.

 

[alldodge]

Yes, it's the lower one, so you need to raise it 1 inch

 

[bcj.jones]

So essentially just raise it one hole?

 

[WIMUSKY]

Start with 1 hole, test it. You may need to go 2 holes... Watch your WOT rpms....

 

[alldodge]

Better to be a tad to high then to low

 

[bcj.jones]

Ideally I want the cavitation plate dead even with the bottom of the hull?

 

[roscoe]

A tiny bit above hull bottom. Usually 1/2" to 1 1/2"

On one of my boats it needed to be 2" above bottom of hull.

 

[Watermann]

Yes the plate right above the prop is correct, the AV plate. As said it should be just above the bottom of the hull.

 

[bcj.jones]

I'll move it up a hole and test it this weekend. Thank yall for the help!

 

[scoflaw]

Cav plate should be clearly visible when on plane. I'm about 2" higher with the straightedge test. Porpoise is now gone.

you'll also get more rpm's, speed, and better gas milage

 

[bcj.jones]

Thank y'all for the help! I'll move it up one hole and try it out this weekend!