My boat will lean slightly to the left at full throttle. Nothing seems to create a heavier left side on the boat to me. Does anyone know what generally causes an unbalanced boat and how to fix it? I don't even know the proper terminology for it.

Does the boat list to port even just a little at rest? If it does then that list will be even more pronounced underway.

There are two types of list. If your boat is listing at rest, the cause can only be from a weight problem and the only solution is a redistribution of weight. Don't forget about trapped water under the deck as a contributor to weight imbalances also.

The second is an underway list with no list at rest. This can be caused by a hull deformity at or below the waterline, a motor trim tab, a motor that is not centered. In other words there is something on the opposite side of the list that is pushing the boat up or something on the list side decreasing the water pressure allowing it to run deeper.

Most commonly it is a hull deformity but eliminate the simple first. They can be inconspicuous also. You may need to take a straight edge and lay it against the hull to see it.

what kind of boat do you have?

lighter boats with high horsepower engines will do this (usually to the right).

you have to balance the weight in the boat with you in the seat until the boat sits relatively flat.
remember you have atleast 2 batteries on the left side, therfore you may need to re-distribute some tackle, etc. to the right side of the boat.
i've found that when a boat leans to the left when on plane the prop can be slipping (not lifting the bow properly) causing the boat to fall over to the left. It can also be from the engine being too high or too low, causing the same problem.

Don't forget about gas if you have dual tanks like I do. I am used to this beacause my fishing buddy out weighs me by about 120 lbs. I burn the gas on his side first.

Does it still lean to the left when you're trimmed out? It will be natural for a boat that has a single engine to lean to the left if you leave the engine completely tucked under and are on plane.

dang I thought this thread was gonna be about politics!

I'm betting you have a whale tale or stabilizer on your engine right? Take it off and see if it still does it....

I put a whale tale on a Bass Tracker last summer and it did exactly this, (lean to the left at full throttle). I have one on my Center Console now and it does the same thing. I'm taking it off this week and I expect the boat to level out at full throttle.

Yes I do have a whale tale. Good advise. I'll try to take it off and see if it works.

By the way, I have a 20' Starcraft Medalist. It only leans to the left when I'm at full throttle.

When you back of to say about 4000rpms it levels out right?

That's EXACTLY what my Bayliner does, and what the tracker did after I put the whale tale on it.

I just took my whale tale off, but won't have the boat on the water again till next weekend when I get to the coast.

My boat leans to the right.... But I was told if I lost 50 lbs, then that would cure the problem!

I have had the same issue, and it was weight that was causing the issue.

I've been using that extra 50 pounds as balast to level my boat. I'm sure I look rather funny standing to the right of my console reaching to the left side for the steering, but it sorta worked for me.

My Ranger does this but only 17 feet, but only does it when I am in bad trim.... which for now is most the time...getting better.. the left lean is helping me get the trim thing correct.

Just for reference, I took my whale tail off my Bayliner before I come down to Port A this weekend, and today I run it for the first time at WOT and she ran nealry perfectly level. Hole shot has suffered some, but at least she custs the water level.

I have the same problem. I believe it to be as described by steve@scp above. I know my prop is dinged up.
It leans to the port side when above 1/2 throttle.

Can you confirm that this is likely an issue with the prop tips being bent back at variouse degrees?

Also and advice on replacing a prop? I have the stock 19 pitch 13 3/4" 3 blade aluminum prop on the boat now.
Shall I go stainless? 4 or 5 blades maybe?