I bought a new to me 2007 WarEagle Tomahawk Coastal 19 with a 90 yamaha 4 stroke. The boat runs on a pad. When accelerating, it does good until wide open throttle. At wot and trimming (already on plane), the boat still gains speed but porpoises…I want the max speed but, no porposing…is this the nature of a padded hull? Is the motor too low?
thx
Even if trimmed up to the point of prop blowout, at wot it shouldn’t porpoise correct?
also, could it be b/c the engine is mounted to low?
on most boats you will porpoise if you have the motor trimmed up too much.
quote:
Originally posted by Floateron most boats you will porpoise if you have the motor trimmed up too much.
even at wot?
Yes at any throttle. I’ve always understood porpoising as an imbalance. The motor or other force is pushing the bow up then the weight of the bow pulls it back down. I’m sure it can be more complex than that but I think that’s the simple explanation. A friend had an underpowered Scout that wouldn’t plane well and when it did it porpoised. A little weight forward would help the plane and porpoising.
it planes off fine…its like it bounces from the pad to the vee…what gets me is it runs faster this way.
Your motor is mounted too low, or it’s a bad hull design. Either way, if you don’t want to raise the motor up a hole, trim tabs will fix your problem.
one of these would help with your problem… not sure exactly what they are called… some sort of stabilizer…
quote:
Originally posted by reel nautione of these would help with your problem… not sure exactly what they are called… some sort of stabilizer…
don’t think that would help b/c when i have the prob, that hydrofoil would be out of the water?
i am thinking engine low or use a diff. prop but, that’s why i am asking on here b/c i am not a mech.
i had the same problem with my 17 seapro bay boat… and that fixed it. i think it acts as kind of a central trim tab, keeping the bow down… but im not a mechanic either…
My keywest 1720 porposes with or without the hydrofoil. 2 people at the console and I can trim back to the console but no further. Send the other person to sit on front deck and can trim it past the console. That is with a person of atleast 160 pounds.
1720 KW 110 Johnson
16’ Bonito 65 Johnson
quote:
Originally posted by carolinacootMy keywest 1720 porposes with or without the hydrofoil. 2 people at the console and I can trim back to the console but no further. Send the other person to sit on front deck and can trim it past the console. That is with a person of atleast 160 pounds.
1720 KW 110 Johnson
16’ Bonito 65 Johnson
i thought about weight distribution, but the front of the boat is a flat deck like a bass boat
Too low causes porposing? I always thought it was too high? The lower the motor, seems like the more likely it would want to rock up? I assume that because I have a heavy 4 stroke on a boat from when 2 stroke were the thing, it just wants to lay deeper int he back that originally.
BG
to low in the water definately causes porpoising
if the boat is setup corrrectly, it shouldnt porpoise at anyspeed or trim angle
my friend has the same boat he put a cobra stabilizer on it.
If your boat is proposing when you tilt or trim up to high and a dolphin, hydrofoil or stabalizer won’t work you can either try trim tabs or a jack plate to raise the motor vertically instead of of “Tilting” the motor up. good luck.
Rippin Lips and Jerking Jaws!
18’ Alumacraft Tunnel w/60 Merc
16’ Camo Tracker w/25 Merc
Have you checked for a hull hook or some other inconsistency in the hull itself? My old Starcraft has a hook in the last foot or so of the hull from a log impact.
Raise the motor on the transom!!! No need to buy anything…