23 CONQUEST List to Port

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Conquest23
Posts: 2
Joined: Wed Jun 05, 2019 10:33 am

23 CONQUEST List to Port

Postby Conquest23 » Wed Jun 05, 2019 10:50 am

We have a 1998 Conquest 23 that's been in the family for more than 15-years and always pushed by a single Mercury 250 XXL EFI. The 23 CONQUEST is a great boat, and we have no problem taking her all over Vineyard and Nantucket sound. But she's ALWAYS on her Port side. The 23 CONQUEST has trim tabs, and they're helpful, but not enough [to overcome the list to Port].

I've been told by a few folks that this is a "feature" of the Conquest 23, and the way to fix it is to re-power with twin 150-HP engine. Short of dropping $30,000 to replace a perfectly good engine, has anyone had success (or ideas) on trimming out a 23 CONQUEST or a similarly tubby boat?

New member here that's lurked for years.

User avatar
Phil T
Posts: 1049
Joined: Thu Oct 22, 2015 6:08 pm
Location: Was Maine, now Kentucky
Contact:

Re: 23 CONQUEST List to Port

Postby Phil T » Wed Jun 05, 2019 12:22 pm

Verify the following information:

Engine mounting height (# of empty holes above top bolt)
Size of trim tabs.
Direction of engine trim anode? @ 5:30, 6 or 6:30?
Are the under deck lockers dry?

Review this thread http://continuouswave.com/ubb/Forum1/HTML/013313.html
Member since 2003
1992 Outrage 17, 1992 Evinrude 115

jimh
Posts: 6616
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 23 CONQUEST List to Port

Postby jimh » Wed Jun 05, 2019 12:57 pm

Your narrative is unclear about the conditions when the 23 CONQUEST exhibits a list to Port. Your description of "ALWAYS" is not easily understood. Some further information is necessary:

Q1: does the list to Port occur when the boat is not underway?

Q2: does the list to Port occur anytime the boat is underway?

Q3; does the list to Port occur only when the boat is on plane?

Further advice can be given once this information is known.

jimh
Posts: 6616
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 23 CONQUEST List to Port

Postby jimh » Wed Jun 05, 2019 4:33 pm

There is a very common trait among many Boston Whaler hulls to list toward windward or lean into the wind when running on plane. For the wind to always be coming onto the boat from only the Port side would be odd and might not explain a perpetual, constant, uncorrectable list to Port, but this known tendency to lean into the wind might also be a factor.

Conquest23
Posts: 2
Joined: Wed Jun 05, 2019 10:33 am

Re: 23 CONQUEST List to Port

Postby Conquest23 » Wed Jun 05, 2019 10:54 pm

jimh, Thanks for the quick reply. Q1: No, Q2: Yes, the list is most sever prior to planing, Q3: Yes.

Phil T, Thank you also. I'll review the link provided and get you the requested specs/details. Might not be until next Friday, as I'm away. I'm 99% sure the trim tabs are the original 9"x9" Bennett tabs (Whaler part # 1020379). And, the lockers are dry.

flymo
Posts: 191
Joined: Thu Oct 22, 2015 2:58 pm

Re: 23 CONQUEST List to Port

Postby flymo » Thu Jun 06, 2019 6:02 am

If the list occurs when the boat is sitting still then you have a weight distribution problem. It is hard to see how switching to twins would help, unless your current motor is mounted off center.

You may wish to experiment with some ballast on the starboard side. First off, move any heavy stored gear from port to starboard, if possible. Then get some friends and see how many people it takes on the starboard side to remove the list. Once you figure out the amount of weight you need, you can figure out how to get it over there permanently - by moving gear around or perhaps adding some fixed ballast.

jimh
Posts: 6616
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 23 CONQUEST List to Port

Postby jimh » Thu Jun 06, 2019 7:53 am

Since the list to Port does not occur when the 23 CONQUEST is not underway, we can rule out weight distribution as the cause.

Since the list is most pronounced while accelerating onto plane, the cause is probably propeller torque. With a single engine turning a right-hand propeller, there will be a tendency for the boat to list to Port.

I would expect this effect could be overcome in a 23 CONQUEST by two methods of compensation. A relatively small boat like a 23-footer will have lateral trim that is sensitive to weight distribution, so having the crew move to Starboard should help correct a list to port while accelerating onto plane and while on plane. On my REVENGE 22 with Whaler Drive, just moving one person laterally a few feet will alter the lateral trim on the boat. Trim tabs should also be effective.

[I deleted some advice I gave because on further reflection it was probably wrong--jimh]

floater
Posts: 106
Joined: Sat Oct 24, 2015 3:55 pm

Re: 23 CONQUEST List to Port

Postby floater » Thu Jun 06, 2019 10:01 am

My Revenge 20 WT was also listing to Port when underway, from acceleration from a standing start to plane. I figured it was the combination of the 130-lbs auxiliary engine and the 50-lbs battery on the Port side.

I installed the Lenco Trim Tabs, and they took care of the problem completely. I lower the Starboard trim tab all the way down and leave the Port side all the way up to correct the list.

jimh
Posts: 6616
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 23 CONQUEST List to Port

Postby jimh » Thu Jun 06, 2019 10:32 am

FLOATER--thanks for the information that you could correct a list to Port with the trim tabs on your REVENGE 20 boat.

When you say "I lower the Starboard trim tab all the way down," are you referring to lowering the Starboard tab into the water? Or to a "DOWN" direction indicated on the control for the Starboard bow?

floater
Posts: 106
Joined: Sat Oct 24, 2015 3:55 pm

Re: 23 CONQUEST List to Port

Postby floater » Fri Jun 07, 2019 10:00 am

My on dash monitor shows the starboard tab deployed down into the water stream. But now that you mention you trim the opposite tab I remember the wiring instructions telling me to wire them backwards. The port toggle moves the starboard tab and vice versa. I will be going out fishing this evening and I will check to see which tab is actually moving when I push the button.

floater
Posts: 106
Joined: Sat Oct 24, 2015 3:55 pm

Re: 23 CONQUEST List to Port

Postby floater » Sat Jun 08, 2019 6:25 am

I took a look at which tab deploys when under way. It turns out it is the port Trim Tab that goes down into the water to correct my list to Port. On my dash I have to press the starboard button to deploy the Port Tab. I will dig up the installation instructions as I do remember them saying that I need to wire the tabs to their opposite switches.

jimh
Posts: 6616
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 23 CONQUEST List to Port

Postby jimh » Sat Jun 08, 2019 8:37 am

floater wrote:...It turns out it is the port Trim Tab that goes down into the water to correct my list to Port.


Thanks for checking and verifying the operation of the tabs that produces the desired outcome. You report sounds reasonable.

Trim tabs are really best thought of as stern lifters. If you put the Port trim tab down into the water, it will tend to make the stern go up on the Port side. If the stern lifts on Port and if the other tab is not in the water at all, the lifting force on the Port side should correct the tendency of the hull to list to Port.

If both tabs are operated in unison, and both go into the water, then the effect is not on the lateral trim but on the fore-and-aft trim. If the stern goes up, then the bow goes down.

I can see where the labeling and wiring could become confusing.