major tipping problem!

daviddsims

Cadet
Joined
Sep 6, 2004
Messages
22
Hey I bought an Avanti 17 feet 1987 ski boat with a 120 mercruiser last fall. Well I have had some major tipping problems with it when I take it out for cruising. When I accelerate soemtimes it will almost tip over to whatever side the most weight is on. My friend said he has never seen one do it that bad before and told me to get rid of it because he thought water might be in the hull and saturated inside the foam. There is no wood floor in it as i checked under carpet and it seem to be fiberglassed. Anybody have idea as to what it can be and a fix to it?
 

daviddsims

Cadet
Joined
Sep 6, 2004
Messages
22
Re: major tipping problem!

Also I took the hydrofoil of that the original owner had on so it is not a hydrofoil problem.
 

prockvoan

Chief Petty Officer
Joined
Jul 27, 2004
Messages
512
Re: major tipping problem!

How is the weight displaced in the boat?Batterys,fuel tank,ect?Another thing to look for is if the bottom of the boat has a cup in it.Trim tads will help,if moving the weight around don't help.
 

daviddsims

Cadet
Joined
Sep 6, 2004
Messages
22
Re: major tipping problem!

The battery is on one side and fuel tank on the other side. Well as long as 2 people are riding I have to keep someone in the middle to balance and it doesnt do it.
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: major tipping problem!

Is the mfgr still in business. Maybe you could find out the dry weight from them then weigh yours. Just because it has a fiberglass floor doesn't mean there is not foam under it. in 1987 that boat had to conform to federal floatation standards.<br /><br />Does it level back out after acceleration? You might consider Smart Tabs but that sounds like it might just be a bandaid to a more serious problem.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: major tipping problem!

Does it ride level in the water when at the dock? That should tell you if you have more weight on one side or the other.
 

daviddsims

Cadet
Joined
Sep 6, 2004
Messages
22
Re: major tipping problem!

yes it rides level when i am cruising and once i get on plane but it is pretty much just when i acclelerate but after it is on plane it is fine.
 

jim dozier

Lieutenant Commander
Joined
Jan 8, 2003
Messages
1,970
Re: major tipping problem!

Where is the cavitation plate in relation to the bottom of the hull? What angle of trim are you running at? Is it tipsy when you are standing still? If it's tipsy at a standstill I would look for hull problems or as suggested above, water in the compartments below the floor. This may sound obvious but have you pulled the plug and drained the hull? If it only happens under power I would suspect engine trim or engine mounting problems.
 

daviddsims

Cadet
Joined
Sep 6, 2004
Messages
22
Re: major tipping problem!

No it is not tipsy standing still. Yes I have drained the hull also. It seems it happens when under power.
 

cc lancer

Petty Officer 1st Class
Joined
Aug 23, 2004
Messages
371
Re: major tipping problem!

Insufficient "wet-ed surface" at the stern of the boat. When you accelerate the bow is coming up reducing the amount of hull in the water. You said when someone is in the middle you don't have the problem.<br /><br />Try trimming the outdrive away from the stern to put more down force on the hull, and see if that improves the handling.<br />My Larson does the same thing, lays over to starboard, if I don't play with the trim button.
 
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