Use of trim tabs bayliner 285-gctid398473

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I have a 2011 Bayliner 285 with the extended swim platform. With 3 adults on board I have not been using the trim tabs to trim the boat and find at 3800 to 4000 rpm boat appears to be trimmed or I think it is.

Is this what others are finding or do you use some trim to bring the bow down. I read somewhere that using the trim tabs creates more drag and reduces fuel consumption but also know if not trimmed properly fuel consumption is reduced.

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I almost always use tabs to get up out of the water, even lightly loaded. It'll just get up quicker regardless of the circumstances. On plane, the point where you should be trimmed at is where you get the most speed per given rpm in normal conditions. That's what I do, other than for weight distribution issues. My boats a 2655, but I beleive the same principle applies. On several occasions I've notices a 1 or so mph increase in speed from putting the tabs down some. Also depends on seas where it'll do best.

[JimMc Guru Find all posts View Profile Close JimMc]

DRIVE TRIM

You TRIM the drive up or down bringing the the bow up or down. You want the the bow up a little for speed, down a little to smooth the ride. Start with the drive all the way down and then adjust up in short bumps.

TRIM TABS

You adjust the Trim Tabs to level the boat Port to Starboard depending on wind and weight distribution. A little goes a long way.

Before I had a trim tab indicator I would always bring both tabs all the way up and then bring one or the other down in small increments/bumps so I could keep track of where they were at. Having a trim tab position indicator makes it a bit easier.

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barclam wrote:
I have a 2011 Bayliner 285 with the extended swim platform. With 3 adults on board I have not been using the trim tabs to trim the boat and find at 3800 to 4000 rpm boat appears to be trimmed or I think it is.

Is this what others are finding or do you use some trim to bring the bow down. I read somewhere that using the trim tabs creates more drag and reduces fuel consumption but also know if not trimmed properly fuel consumption is reduced.

I assume you mean fuel economy aka miles per gallon.

[Spyderweb2 Seasoned Member Find all posts View Profile Close Spyderweb2]

What Jim said. I get up on plane with trim all the way down. With only 2 onboard, I usually have the tabs all the way up. With more weight, I'll usually put them down to help the boat get on plane.

Once up on plane, at around 3600 rpm for 2 of us, 3800 or so with more people, I'll raise the outdrive up about about 5 clicks. With it all the way down and on plane, the motor/outdrive seems to "growl". Raising it up (which raises the bow slightly) smooths out the sound from the rear of the boat. Go too far up, and it starts to "growl" again.

Once the trim is set, I'll usually drop one or the other trim tab to level the boat out (left to right). It's seems quite sensitive to a side wind or current, and wants to lean. Just a little bit of tab levels her out.

If driving through pounding waves (not often), I'll drop both the trim tabs to drop the bow to smooth the ride out a little.

Paul

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JimMc wrote:
I assume you mean fuel economy aka miles per gallon.

Hello Jim

Getting late. Your right, I should have said not being trimmed right increases fuel consumption or reduces mpg.

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Spyderweb2 wrote:
If driving through pounding waves (not often), I'll drop both the trim tabs to drop the bow to smooth the ride out a little.

Paul

If in following sea conditions never lower the trim tabs as it can badly effect handling.

[Patrevan Seasoned Member Find all posts View Profile Close Patrevan]

barclam wrote:
I have a 2011 Bayliner 285 with the extended swim platform. With 3 adults on board I have not been using the trim tabs to trim the boat and find at 3800 to 4000 rpm boat appears to be trimmed or I think it is.

Is this what others are finding or do you use some trim to bring the bow down. I read somewhere that using the trim tabs creates more drag and reduces fuel consumption but also know if not trimmed properly fuel consumption is reduced.

I'm guessing you have the 5.7 MPI w/B3? Lightly to moderately loaded, your not apt to really need the tabs most of the time. IMO, it's good practice to use the tabs as a part of routine vessel use. That which we do routinely becomes automatic at some point, without thought. When you reach the point of intuitively adjusting your systems without need to look at guages and switches is when you have truly mastered your boat. Conisder a Flo-Scan if you want to learn optimium fuel economy quicker than doing it the hard way.

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JimMc wrote:
If in following sea conditions never lower the trim tabs as it can badly effect handling.

Thanks Jim

[Davidlyne Guru Find all posts View Profile Close Davidlyne]

On my 2655 I start off with tabs nearly full down, drive almost fully in, then trim the drive out a little, then adjust the tabs up until I get the attitude I want.

[Tabman With Honors Find all posts View Profile Close Tabman]

All Boats are different when it comes to using Trim Tabs and by far the best input is from the other members who have run Trim Tabs on your model Bayliner, or similar ones.

Below is a "Trim Tab 101" I wrote to help users get a general overview of their use. The best advice is to use them in short bursts and let the boat settle down between corrections. Also I always encourage careful experimentation to find what is best for you and your particular boat.

Tom McGow

Bennett Marine

Getting and Staying Trimmed

All boats assume different fore to aft attitudes at different throttle settings and vary in sensitivity to lateral weight distribution.

A boat's optimum running attitude is determined by the operator. While some people may define optimum running attitude as the highest possible speed for a given amount of engine RPMs, others desire the best possible fuel economy, yet others may be trimming the boat to get just the right mix of speed and wake (such as for waterskiing.)

Optimum running attitude is when the boat is running to the operator's satisfaction for the given operating conditions. There are as many optimum running attitudes as there are boats and boat owners

A good way to determine a boats optimum running angle (see side bar Optimum Running Attitude) is to run the boat lightly loaded at full speed in calm water. During this test observe the boat's bow in relation to the horizon. Most boats run at or near their optimum attitude under these conditions. This should give you a feel for the appearance of the wake and bow spray when running at an efficient attitude. Note that not all boats will achieve their optimum running attitude under these conditions. Some boats will benefit from extra lift even when running at their maximum throttle settings. If you feel the boat will benefit from added bow down trim when running at speed start with the trim tabs fully up and deflect the trim tabs in short bursts. Be alert to changes in the boats handling, as you bring the bow down. Observe any changes in RPMs and/or speed. Adjust power trim if applicable.

Indications of Running Untrimmed

When a boat is running untrimmed the bow spray will exit the sides of the boat far aft. The stern wave (wake) is high and curling like a breaker on the beach. The rooster tail is high and close to the stern. The engine is laboring and the ride tends to be less smooth.

Indications of Running Trimmed

The bow spray moves forward and is flung not as far from the boat. The wake diminishes in height, as the rooster tail flattens out and moves away from the boat. The engine is operating under less load as evidenced by the tachometer and speed as well as sounding "less strained".

One Step at a Time

The key to obtaining optimal results from trim tabs is to operate them in short "bursts" and let the boat react before making another adjustment. The amount of time between corrections is influenced by the size of the trim tabs and the boat's speed. This will help avoid overtrimming or ending up with one tab too far down when correcting lateral trim. You will quickly become acquainted with a boat's particular traits.

Take Off

Properly sized trim tabs can significantly reduce the time needed to get up on plane. They also allow a boat to keep its bow down and stay on plane at lower speeds.

As the throttle is advanced the stern of the boat begins to squat, lifting the bow. As the boat accelerates, push the bow down position of the helm control in short bursts. The boat reacts by the stern lifting, the bow coming down, speed increasing, and reduced engine laboring. If you over do it and deflect the tabs too far the boat will end up overtrimmed. When over trimmed, the steering becomes "over sensitive" and wants to pull off course to port or starboard. If this occurs, operate the control "bow up" until the desired attitude is established.



Getting the Most from Power Trim

Adjust the trim tabs to achieve the desired running attitude. Then use the power trim to position the propeller thrust parallel to the water flow. If necessary, re-adjust the trim tabs to fine tune the attitude. By observing the boat's speed and engine RPMs the best combination of trim tabs and power trim will be apparent. Trim tab angle indicators and a power trim angle indicator are particularly useful in duplicating effective settings.

Trimming to Sea Conditions

When running into a head sea you want to trim the bow down so the sharp forward sections of the boat do their work cleaving the waves. This provides the most comfortable ride and minimizes stress on the boat (and passengers). In a following sea the tabs should be fully retracted for maximum steering response.

Correction of a List

The normal control setup for trim tabs operates in relation to the desired changes in trim and not the actual movement of the tabs. Therefore, do not think about what the tabs are doing, but rather on the control and what you want the boat to do. As above, make the corrections in bursts and allow the boat to settle to the new settings. You may find it easier to correct the boat's fore and aft attitude before you correct the side to side trim.



Correction of Porpoising

Operate the tabs in very short bursts of about half a second. Continue until porpoising subsides. The objective is to have only a very slight amount of tab deflection, just the amount needed to cure the up and down motion of the bow.