bow bouncing tracker targa

[Terry]

My dad has a tracker targ 17' with a 125 merc and a 21 pitch aluminum 3 blade prop and the bow bounces all the time a higher speeds no matter how the trim is adjusted, any help will be appreciated.

[Dennis W]

The best ad easiest solution is simply to install a fin, ( such as the Dol-fin ) on the anti-cavitation plate of the motor. Some will tell you to raise your motor, install a jack-plate etc., I personaly wouldn't waste my time or put that much effort into it. By simply installing the fin, you will be able to trim higher without porpoising, and should be able to gain about 3 mph. The cause for the porpoising is simply the hull design. A shorter, wide boat is the most prone to porpoisng, If your boat was 18" more narrow, the problem would be much less evident. Don't sweat this issue, just slow down and enjoy a comfortable ride. Your kidneys will thank you, and your boat will thank you. Remember, if it doesn't feel good to you, it doesn't feel good to your boat.

[Terry]

The boat has a hydrofoil and trolling plate from cabelas on it already.

[DennisW]

If you already have a fin, and have put reasonable thought into the weight and and balance, then there really isn't much more that you can do. All boats, ( including offshore racers ), will porpoise under certain speeds and water conditions. Your boat was designed more for room and stability than high speed performance. If you can achieve a comfortable, non-porpoising cruising speed, ( in calm water conditions ), of about 35 mph, then you should be happy. if you want to go faster without porpoising, you will need a different boat. Sorry, but thats what I honestly believe. I at one time owned the the same boat that you have, and was not ever happy with the ride.

[FJH1]

I think we might need some more info on this boat. Has it always bounced or is this something new? My reason for asking this is if you add more weight to the stern of a boat you can experience the porpoising that you describe. Does the boat have a kicker motor, if yes, was it recently added? Is there a lot of weight located in the rear (all batteries, tackle, full livewell in the rear...). What hole is the motor mounted on? If it's all the way down you might consider raising it a hole. Have you tried shifting weight to the bow (fill front well, empty the rear well, move tackle forward...)? One other thing, is there water in the bilge? I know this sounds stupid but a good amount of water in the bilge can make the boat stern heavy. If you can answer some of these questions the people on this board might be able to diagnose the problem.

Best Regards,

FJH

[Terry]

The boat has done this since it was new. The boat is a 1999 model it has no kicker the live well is up front, I think the motor is in the second hole.

[REW]

We went through all this about a year ago.
A very simple and inexpensive fix.
1. Remove the fin - not needed.
2. Add trim tabs on each side of the transom at the bottom edge of the transom.
3. Make these trim tabs about 12 inches long and 2 inches wide. You can make them out of 2X2X1/8 inch aluminum angle. Simply cut a couple of 12 inche lengths and screw them to the lower edge of the hull at the very low edge of the transom.
Make sure that the outer edge of the trim tab is at least 3 - 4 inches inboard from the very extreme outer edge of the hull. I think that you will find that this will eliminate your bounce.

4. If you find that your boat plows too much after adding the trim tabs - remove the trim tabs and gently bend up the tabs up in 1/16-1/8" increments until the plowing stops.

When you are getting porpoising -- the entire boat is balancing on the lower back edge of the transom. The addition of trim tabs, create a downward stabilizing force, to keep the bow down. At some point -- as the bow rises, and the trim tab digs into the water -- the downward force of the trim tab, will equal the upward bounce of the bow -- and stability will happen. If your trim tabs are too large, or are angled down too far -- there will be too large a downward force, which will keep the bow from rising at all out of the water.

+++++++++++++++++++++++++++++++++++++++++++++++++
Another fix, that works for some Targas as well as other boats -- and that is the addition of motor transom wedges. These typically come in a set of two -- one for each side of the motor, complete with bolt holes that will match all common motor bolt patterns. The way that these transom wedges work -- is that they are thicker at the top than at the bottom. By removing the motor - and installing the wedges between the boat and the motor -- the boat owner achieves an additonal 5 degrees 'tuck under". i.e. the motor may be trimmed another 5 degrees under the boat. In many boats this also fixes the porpoising problem. ON some boats -- the combination of hull design transom angle, and weight placement results in not enough downward force being generated by the motor at any trim angle. If you find that you get bounce at any speed and witht the motor fully trimmed in -- you might need transom wedges, in addition to the trim tabs.

p.s.
When you install the trim tabs -- drill at least 6 holes in the trim tabs. This means a hole every two inches. There is a lot of force generated by the trim tabs, and you don't want them pulled off the boat. Use a good marine sealant to seals the stainless steel screws at the time that you mount the trim tabs, since all these holes, will be below the water line.

[Jim/UT]

Terry,

I'm working with a similar thing. I have the trim tabs and they work fairly well to resolve the porpoising issue. Tweak as REW described. The trim tabs do take up a lot of space and have caused some problems with my transducer placement that I am still working on, was thinking of going with the hydrofoil and remove the trim tabs, similar to the setup you have. One thing I notice with the trim tabs is I blow out the prop on the slightest turn, it doesn't take much. Another reason to try the hydrofoil I guess. One thing I have noticed that makes a fairly big difference in my porpoising is filling my front livewell. The extra weight up front makes a significant improvement. I always used my rear livewell in the past, switched to the front this year. Putting the motor up one hole reduced porpoising a little, but also increased prop blowout in turns. The trim tabs drove blowout to the annoying level. I still don't have the perfect solution but am slowly moving towards an adequate solution. I'll have to spend less time fishing and more time working on the boat I guess.

Good Luck!

[FJH1]

You might try adding more tip cupping to your prop. This will really help with the blow out that you are experiencing.

Best Regards,

FJH

[Jim/UT]

I went from a 17 plain to a 19 cup, didn't notice any difference. Dealer says the trim tabs move so much of the back end up out of the water it is hard to get a bite. I was thinking of moving the motor back down a hole, but then I get back into the whole porpoising thing again. There are no easy solutions it seems.

Thanks!

Jim

[FJH1]

You might have to add more cup. I say this because I have a Lund 1800 Pro V SE with a Merc 175 efi and a Panther Jack Lift. With my aluminum stock prop I couldn't even make the slightest turn with out the prop blowing out and this was with the jackplate as far down as possible (the motor was actually LOWER that the lowest hole). After I was done with the break in procedure I talked to a prop specialist in my area and he had me test numerous props. We settled on a Trophy Plus (four blade). I would still get some blow out on harder turns with the jack lift raised a couple of inches. He said this was no problem and added in a bit more tip cupping. I can now raise my jack lift 3 inches (at least), draw great water pressure, and do hairpin turns without the slightest inkling of blowout. Again, what works for my boat/motor combo might not work for you but if you have that opportunity to test a prop with more tip cupping it might be worth the trouble.

Best Regards,

FJH

[REW]

I had the same problem after adding trim tabs.
I installed a Raker Stainless prop -- lots of rake and a lot of cup. No more blowout at any trim setting.

Take care

REW