[loonzter]

Just had my brand new outboard mounted on my 1986 20' Proline CC and the motor runs just great. I do however have an issue with the boat listing to the right when I get up on plane and give it some throttle. At first I thought it was the old swim platform perhaps dragging in the water so I removed it but the list is still there. I asked the guy who mounted the engine and he said it might be the transducer on the starboard side?? He suggested lifting it out of the water and driving the boat, it the list is still there he said I could buy fixed trim tabs to mount to my transom. I assume by adding some drag on the port stern it should correct the tilt to the right?? It's not the fin on the bottom of the motor (steering) because the boat tracks straight while underway, it just tips to the right?? any thoughts

 

[MakoMike]

Does the boat sit level at rest? Is there anything besdies the transducer dragging the water? I would at least measure the mounting holes on the motor to make sure it sits dead center on the boat before going the trim tab route. If I did install trim tabs I would install adjustables.

 

[loonzter]

Boat sits level when not under power and motor is mounted dead on the center of the transom, nothing else on the starboard side now but the transducer. Didn't really consider mounting hydraulic or whatever type trim tabs that adjust via a control. I assume there is a low cost somthing I can screw or bolt onto the transom that I can manually adjust till the boat rides level. Set it and forget it, or can I make my own??

 

[Fishbust]

List....

That boat is too small for needing tabs. In fact I have never been on a boat that needed tabs to correct for an engineering flaw. The ONLY thing I have ever used tabs for is ONE TAB to correct for a quartering sea heading back home from offshore to make a smoother ride for passengers.

It is not likely the transducer either. It takes more than that to lean over a hull underway.

Maybe all that foam is soaked on one side under deck. Not a pretty diagnosis I know but that is what comes to mind to create a lot of weight on one side. But like Mike says...if it leans at rest also....not good and the best scenario would be you have batteries and too much other gear stored to one side of the boat and need to balance things better. I hope the situation is the latter for you.

 

[647394]

got the same problem

i have the same problem, i have a 17' CC, 115hp mariner...boat lists to the left...bad sometimes. Been researching it all day. Seems to be the cause of prop torque. The prop spins to the right, so the equal and opposite reaction is the boat lists to the left. This shouldnt be caused by the transducer. And if she sits level at rest i dont think it would be an issue of off balance weight. at a very slow plane my boat is ok...but as soon as i give it a bit more throttle it lists left. Alot of what i read indicates tabs will help, though im not 100% sure of this. I want to get a hydrofoil anyway so im trying to see if it would help the leaning at all. Just a disclaimer, im not a pro boat mechanic

just been reading about it all day....try googling "prop torque"

good luck and post if u solve it please

 

[kenc1061]

I had the same boat a few years ago & the same problem. Talked to proline & investigated alot to finally figure out I had water trapped under the foam along side the starboard stringer. seems the foam didnt fill the entire void & once the water gets in it has no means to escape. after installing a couple of deck plates to figure it out I wound up driling a 1" hole from the bilge side through the stringer along the hull following the deadrise, ran blowers to dry everything out & then a couple of coats of epoxy to seal the raw edges. solved my problem & other than that it was a good boat, had it for 5 yrs & sold it for what I had paid. hope this helps

 

[loonzter]

I'm starting to believe I'm going to have to live with this. The boat really isn't rigged with a lot of stuff, don't even have the cooler seat on it yet. Batteries are under the console not on one side or the other. Being the motor is mounted right in the center I really don't know what else it could be?? Thought a small wing just under the the bottom of the port side would provide a little balance to level the boat under power. Not really full blown trim tabs.

 

[loonzter]

You just started cutting out holes in the deck and installing deck plates until you found some water? I just don't feel I'll be going that far, I'd leave it as it is before I started doing that! Maybe I'll move the transducer over to the port side to provide a little drag?

 

[MakoMike]

If the boat does not list at rest then its probably not a weight distribution problem. Is your helm to starboard? Could it be your weight while running the boat that is throwing it off? Are you sure there is no list at rest? Did you put a level on the deck or just eyeball it? Small differences in trim at rest can be greatly magnified at speed. Prop torque is a common problem, but it seems based on what you have said that the trim is off by too much to be solely the result of prop torque.

There are very few boats that will not benefit from adjustable trim tabs in some sea conditions/loading configurations, which is why I said to get the adjustables if you are going to add tabs.

 

[kenc1061]

maybe you won't have to put in deck plates, I did it to find the problem & dry everything out, but you can drill the drain from the bilge deck plate. Just to trouble shoot you can put 10 or 15 gal of water in the port fish box & see if that levels you out. When I drilled mine I was amazed at the amount of water & sand that came gushing out, probaly from years of collecting in there.I wound up drilling a drain in the port side also but nothing was trapped in there, even proline admited there should have been drains or at least weep holes installed at the factory. Just something that was overlooked at the time

 

[loonzter]

kenc, "you can drill the drain from the bilge deck plate" I'm trying to figure out what you mean by this?? In the stern of my Proline there is an inspection plate under which the bilge is located. Are you saying you drilled up towards the bow through the foam from this access port?

 

[loonzter]

I just remembered there is a deck plate in the center of this boat (new boat for me), even thought it's about 4' long the problem is it runs under the console, so to lift it would require removing the console. I'm starting to scare myself just typing this.....

 

[647394]

whoa

removing the CC and deck plate is no biggy...just go easy and it should come up ok....u can just kinda lean the CC up w/out disconnecting any controls...and remove that plate...things start to suck when u see the big ol gas tank that lives under there...assuming u have an onboard tank, not protable....turns it into a bigger project...not impossible, but more involved.... and sucky if u find no water and it is just prop torque. Im thinkin if u pop the hatch in the rear, @ the bilge pump...and drill to port or starboard into the foam....it may work to check if its holding water....im havin the SAME problem with my 17'CC proline...but i still feel its due to prop torque or something like that....but i may look into checkin for water to eliminate it as a factor.....that boat leaning really sucks and it just make ya mad while driving toward a straight horizon..seeing the bow crooked

good luck

 

[loonzter]

Orph, I hear ya, I'm so excited with this boat. My new 115 Mercury Optimax runs like a dream and if the smartcraft guage is correct really sips gas!!! But like you said it kinda sukks to look out over the bow and have everything ****ed!

 

[658261]

Ok my answer may be a little off but it is something that happend to me I have a 1988 19 ft bonito (thundercraft knock off???) with a 98 merc 150. The boat is kinda poorly made but I take good care of her.. well anyway the center console was not a cetered it was off by 3 inches and at higher speeds caused my boat to list.

I unscrewed the console and glassed it down and it straitend her right out.

This probably isnt your problem but I figured you might want to take a measuring tape to te console befor you start drilling holes or buying trim tabs.
Good luck kep us updated on what the problem is when you figure it out.

 

[clementine]

easy fix:
put a 5 gallon bucket of water on the port side of the boat or just stand a little to starboard. I wouldn't go pulling up the console and doing whatever you're planning if the boat doesn't list at the dock. Sounds like a design flaw or something.

 

[647394]

yeah dude, kinda embarrising too when i bring friends out as it seems more weight, no matter if it is centered...makes it a little worse. Im proly gonna try a hydrofoil....which i wanted anyway, seems like what ive read suggests trim tabs but i havent got too much money to spend. ill let u know if it helps....if u find anything that fixes your problem, please pm me and let me know...thanks man, good luck

 

[GoingFishing]

Sure it's not the gas tank?

Sometimes tanks are not fitted square to the centerline keel. Is the listing affected when you add gas to her? I'm just assuming it is a below deck tank, you might just be using a portable above deck tank, but something to consider...

 

[MACKS]

Just a thought,are you sure you have the right prop,does it reach the max rpm when you run full throtle,maybe there is to much cup in the prop.

 

[PaddleOn]

Its obvious:
Its the prop and the torque the prop is creating to the boat.

Your old engine: No list
Your new engine: it lists

Same boat but new engine.
Never leaned now it does.
Its rather obvious where the problem begins?

Its the torque or what MACK just wrote about the prop.

This post edited by PaddleOn 08:11 PM 05/20/2008