New Engine Causes List to Port

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Waterfun
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New Engine Causes List to Port

Postby Waterfun » Thu Jun 13, 2024 7:58 pm

In the 2023 boating season I re-powered my 2005 190 NANTUCKET with a new Mercury 150-HP engine, The boat now has a list to Port when at the dock and also on the water.

Q1: is this new list to Port due to a "foam soak"?

Q2: is this new list to due to the "balance" of the engine?

I welcome any thoughts.

jimh
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Re: New Engine Causes List to Port

Postby jimh » Fri Jun 14, 2024 8:28 am

Waterfun wrote:The boat now has a list to Port when at the dock and also on the water.
If "on the water" means while the boat is underway and at higher speed so the hull is on plane, a list to port can be caused by the propeller torque. This behavior is common in a single engine outboard boat with a right-hand propeller.

Perhaps the trim tab on the engine is not properly set. To learn how to set the trim tab on the engine, see this section of an older Boston Whaler Owner's Manual that I have converted into an on-line HTML document:

https://continuouswave.com/whaler/refer ... ml#trimTab

A list to Port can also occur when the boat has considerable wind hitting it from the Port side. The helmsman will tend to steer to the left to compensate. If you only notice a list to Port when making headway into winds from the Post side of the boat, that could be the cause.

As for an unoccupied boat at rest in its static trim suddenly developing a list to Port where before there was no list to Port, the only reasonable explanation for that is there has been a shift in weight. Heavy items like a large storage battery that is located far outboard from keel center line will cause a list.

Typically on Boston Whaler boats the engine starting battery is always rigged on the Starboard side at the transom. The cockpit sump is also on the Starboard side near the transom. The weight of the battery imparts a slight list to Starboard, and any rain water coming onto the cockpit will tend to drain to the Starboard side and run into the cockpit sump when no one is on the boat to disturb the natural trim of the hull.

I have no idea exactly how your 2005 190 NANTUCKET battery and cockpit sump are arranged, but if for some reason the sump and the engine battery are on Port, that could explain the list to Port in static trim with no one on the boat.

As for a "foam soak" (which I am not sure exactly what that phrase means), in order for there to be ingress of water into a Unibond hull there must be damage to the hull laminate which exposes the foam to continuing contact with water under some pressure. Maybe you ran into a big rock and tore out a large section of the bottom of the 190 NANTUCKET and haven't noticed the damage.

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Phil T
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Re: New Engine Causes List to Port

Postby Phil T » Mon Jun 17, 2024 8:04 pm

Most likely trim tab.

It needs to be set so when looking from the back of the engine, straight down, the tail is pointing at the 5:30 position.

How much weight needs to be moved from where to where to establish lateral trim.
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Waterfun
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New Engine Causes List to Port

Postby Waterfun » Fri Jul 05, 2024 5:16 pm

[In an entirely new thread the author says] I posted previously about my [Boston Whaler 2005 190 NANTUCKET boat having ] a lean to port at rest and under power.

[That entirely new thread was on precisely the same topic as this earlier thread. I have combined the new topic with the old topic because the two topics were precisely the same topic. Please do not start a new thread when you purpose is to update an existing thread with new information--Moderator]

I have ensured the additional weight of the batteries as as close to center as possible.

I did re-power with a new 150 [HP engine of unspecified manufacturer and model] last year [i,e, 2023] but the overall [engine] weight change is negligible.

I have confirmed [that in the hull there are] no holes on the [hull] bottom.

As shown below in FIgure 1, [at static trim the hull has] about a 2-inch lean at the stern.

unnamed.jpeg
FIg. 1. The static trim of a 190 NANTUCKET showing list to Port.
unnamed.jpeg (63.77 KiB) Viewed 10966 times


[The recent behavior of the hull at static trim to list to Port has me] really stumped.

Shifting around people [when underway] nder power to get more weight to the Starboard side so that [the hull] moves through the water at level is not ideal.

Give me [further advice on how to remedy the tendency for the hull of my 2005 190 NANTUCKET boat to exhibit a list to port in static trim].

jimh
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Re: New Engine Causes List to Port

Postby jimh » Fri Jul 05, 2024 5:34 pm

If the hull exhibits a list to Port when at rest, and the list is not being caused by the mooring lines that tie the boat to the pier, then the only reasonably basis for the hull to list to Port is due to uneven distribution of weight in the hull.