Aluminum fishing boat tilts to the right when on plane - what gives?!

saltystick · July 05, 2018, 08:58:14 PM

A month ago I bought a Grumman Oneida aluminum fishing boat with 50hp engine. When on plane at about 30 mph or more, the entire hull tilts some to the right- towards the driver side. Any ideas?

I've put bricks in the rod locker on the left side but it still does it even with the front livewell filled.

The engine is centered though the starting battery is to right in the stern; trolling motor battery centered in the bow.

Sandman7925 · July 05, 2018, 09:15:40 PM

Does your motor have a counterclockwise spin at the prop?

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saltystick · July 05, 2018, 11:24:27 PM

I'm not sure. Would that cause the bow to tilt to the right on plane? I would imagine that the counterclockwise spin would only occur in reverse.

bassmanstan · July 06, 2018, 03:06:43 AM

How far tilt are we talking, on a smaller aluminum boat like that, I tend to think that the combined weight of you and the battery would be enough to make it tilt slightly. Is it just with you or does it do it with another person along. It might have to do with the prop spin too. My 15' fiberglass tilts slightly with just me in, but it does level off once I trim up on plane.

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bassmanstan · July 06, 2018, 03:08:26 AM

It could be that you have a counter clockwise motor, you usually only have that with twins, but if that's the case that would make it lean more too.

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WTodd · July 06, 2018, 07:36:42 AM

I think Stan has the answer; depending on the size of the boat it could be you. Can you sit in the middle of the boat after it's in plane to see if it straightens out?

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merc1997 · July 06, 2018, 09:06:58 AM

if you do not have trim on the motor, then you will need to do some re-arranging your weight in the boat. batteries to the left side. tackle stored to the left side. one other option that would help this is to put a small hydro-foil on your engine. this will also aide in leveling the boat while underway.

bo

saltystick · July 06, 2018, 09:20:32 AM

First of all THANKS SO MUCH FOR YOUR CONTRIBUTIONS!!

Here's a bit info that adds to the mystery:

100 lbs of bricks were added to the left side rod locker.
My partner sits in the seat more toward the midline (not behind me).
I always trim the motor when on plane for best gas economy.
Livewell is usually empty but it might make the tilt worse if the water shifts to the right with a tilted bow.

Tilt is about 20 degrees no matter, more with only me and no bricks in the boat.

Sandman7925 · July 06, 2018, 10:20:10 AM

20 degrees is allot. Hell when I worked on drill ships the Derrick was designed to break away at 20 degrees.

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WTodd · July 06, 2018, 10:22:43 AM

Has the hull ever been damaged?

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big g · July 06, 2018, 01:09:39 PM

Weight distribution is a big thing in a smaller light boat. If I bring a big person with a lot of tackle all on the left side, the boat handles differently.

Oldfart9999 · July 06, 2018, 05:28:34 PM

A hydrofoil should help, it'll help you get on plane faster also. Have you tried to adjust the torque fin(not sure what it's called) just above the prop?
Rodney

saltystick · July 06, 2018, 06:41:13 PM

Boat and everything that came with it are brand new- boat been out only 3x.

I thought about using a hydrofoil which did great for my 90 hp Merc on my Ranger, but this boat gets on plane fast and holds tight to curves. No reason to get it seeing as how the tilt will happen no matter.

Yea 20 degrees is a lot of tilt and I'm not a happy boater having spent over 22k for it!

Bud Kennedy · July 06, 2018, 06:59:06 PM

Just curious, have you inspected the trim tab on the bottom of the cavitation plate. For the most part this device should be in direct alignment front to back. If it is rotated to one side or another this can create a problem similar to what you describe. Also, I may have missed your answer but do you have trim and tilt on this motor?

WTodd · July 06, 2018, 08:05:10 PM

Agree with Bud; easy check & fix

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saltystick · July 07, 2018, 05:05:45 AM

I'll check the trim tab. It's a wonder Grumman rep didn't suggest it.

Oldfart9999 · July 07, 2018, 07:35:03 AM

I would check with your dealer, if the trim tab needs adjusting they should do it no charge, I've not seen set straight. That's what I meant when I said torque thingy, I'm old and forgetful.

Rodney

merc1997 · July 07, 2018, 09:59:05 AM

here is another thing that i would check. is the motor sitting flush down on top of transom, or has there been mounting bolt holes drilled through transom?? if bolts through transom, you need to level boat on trailer, mark the center line of the back of the boat, and then drop a plumbob and see if the lower unit and prop shaft are in line with the plumbob. i have seen it before where the holes were not square to the world and that made the center line of engine off center by more degrees than one would think down at the prop. if this has happened, it would account for your boat listing while going in a straight line.

just another piece of problem solving to check to solve this annoying issue.

bo