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  My 1998 Boston Whaler Ventura leans to port when underway.

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Author Topic:   My 1998 Boston Whaler Ventura leans to port when underway.
whaleofatale posted 07-28-2009 12:35 PM ET (US)   Profile for whaleofatale   Send Email to whaleofatale  
My 1998 Boston Whaler Ventura leans to port when underway. It will do this with everyone and everything on the starboard side. I have to almost stop to get her back level, she will lean WAY over. It does it more with a full tank of fuel and in choppy conditions. Any suggestions?

Tom W Clark posted 07-28-2009 01:12 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Adjust the trim tab on the motor.

http://continuouswave.com/whaler/reference/manual18-25/operations. html#trimTab

Tom W Clark posted 07-28-2009 01:14 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Also, be sure to trim the motor out once you are underway.

Be sure the motor is mounted "two holes up" on the transom.

whaleofatale posted 07-28-2009 01:50 PM ET (US)     Profile for whaleofatale  Send Email to whaleofatale     
The link you gave me says I need to install trim tabs, the way I read it.

“Large propellers on high horsepower engines normally create port list conditions on "V" hulls. If desired, the installation of trim tabs will correct this condition. The installation of a transom mounted transducer on the port side will also reduce port list.”

I have a transducer on the starboard side and that may be part of the problem as it says a port mounted transducer would reduce port list.


Thanks for your help.

Tom W Clark posted 07-28-2009 01:53 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Uh, no, that is the paragraph below the isntuction for TYRIM TAB ADJUSTMENT. Let me quote from that owner's manual:

"TRIM TAB ADJUSTMENT

On larger Outboard motors, there is a steering trim tab located on the bottom of the cavitation plate, just aft of the propeller. It is adjustable and has been installed on the engine to correct for propeller torque.

Adjustment of the trim tab should be done after you've gone through the steps of proper tilt adjustment.

The boat should be operated with a normal load on board in a straight line. Incorrect trim tab adjustment will cause the boat to turn to the left or to the right when your hand are removed from the steering wheel. Be careful when removing your hands from the steering wheel; a tilt tab incorrectly positioned may cause the boat to turn violently.

To adjust the trim tab, loosen the securing bolts, as per the engine manufacturer's instructions, and move the trim tab in the direction the boat pulls. For example, if the boat pulls to starboard, move the trailing edge of the trim tab to starboard. Make these adjustments in small increments and test the results. The object is to create a "hands off straight line" steering condition for the normal operating speed. It is not possible to eliminate steering pull throughout the engine speed range.

Remember, tilt adjustment may affect steering torque as much as the trim tab. With Outboard engines equipped with power trim this becomes particularly important. When under way, experiment with trim settings to neutralize steering pull."

TRAFFICLAWYER posted 07-28-2009 02:41 PM ET (US)     Profile for TRAFFICLAWYER    
I had a 18' Ventura 1998 and a 2001 21' Ventura with no list issues. Do you have a CR motor???????

Check motor hight, trim, sacraficial angle, prop.

whaleofatale posted 07-28-2009 03:19 PM ET (US)     Profile for whaleofatale  Send Email to whaleofatale     
I have a ‘98 20 footer. The motor in the second hole from the top and the trim tab is about 20 degrees to port looking from the back. It tracks almost perfectly straight but is hard to turn to port. I have upgraded to hydraulics and that helped the steering some.
We love this boat! You can take it to the lake for skiing and tubing or take her 40+ miles offshore chasing the Big ones.
whaleofatale posted 07-28-2009 03:21 PM ET (US)     Profile for whaleofatale  Send Email to whaleofatale     
Do you have a CR motor? No
K Albus posted 07-28-2009 04:00 PM ET (US)     Profile for K Albus  Send Email to K Albus     
Your statement that the boat is hard to turn to port leads me to believe that you are not properly adjusting the trim. With a single motor and no trim tabs, you should trim the motor all the way down (or in) when taking off. Once you get on plane, you should gradually trim the motor up (or out) until the motor's anti-ventilation plate is approximately parallel to the keel of the boat. Since you can't run back and look at the anti-ventilation plate while you're driving the boat, one way to tell that the motor is getting close to neutral trim is that the steering will get "easy" in both directions.

From a neutral trim position, you want to trim the motor either up or down to compensate for wind and wave conditions. For instance, if the water is very choppy, you may want to keep the motor trimmed all the way down. This will make for a more comfortable ride as the bow will be better positioned to "cut" the waves, but the boat will be harder to steer. If the water is very calm, you can trim the motor up from the neutral position in order to gain more speed, but at some point the boat may begin to porpoise or chine-walk.

I don't know your experience level, but I have seen a number of new boaters who always operate their boat with the motor trimmed all the way down. Doing so can lead to a list and hard steering.

whaleofatale posted 07-28-2009 04:37 PM ET (US)     Profile for whaleofatale  Send Email to whaleofatale     
I usually trim the motor up maxing out the rpm's. It steers a lot better there but is still a lot more difficult to turn to port.
When it is choppy I do keep the trim down or she likes to jump out of the water.


I have had a 13' Whaler from age 12. I have owned a 25' Whaler and several other boats of assorted sizes. I still consider myself a novice boater.

highanddry posted 07-28-2009 04:41 PM ET (US)     Profile for highanddry  Send Email to highanddry     
Lenco tabs will fix you up, best thing ever. Conditions I could not stay on plane in i can now charge through.
Tom W Clark posted 07-28-2009 05:59 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Again, I suggest the trim tab needs adjusting. If it is hard to turn to port, then it "pulls" to starboard and you need to move the trailing edge of the trim to starboard as outlined in the instructions provided above.

"...the trim tab is about 20 degrees to port looking from the back"

Well, there's your problem. The trim tab should be set so the trailing edge is to starboard, not port.

Tom W Clark posted 07-28-2009 06:01 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
"The motor in the second hole from the top...'

The boat will do better with the motor moved up one more set of holes (3/4") to the third set of holes from the top ("two holes up").

whaleofatale posted 07-28-2009 06:19 PM ET (US)     Profile for whaleofatale  Send Email to whaleofatale     
I will adjust the trim tab when I take it out this weekend. I'll report back next week.
highanddry posted 07-28-2009 08:38 PM ET (US)     Profile for highanddry  Send Email to highanddry     
Not to disagree with the gods but pulling is not the same as leaning, if the boat is leaning to one side or the other underway which is generally the result of propeller torque and or poor loading and nothing to do with the trim tab on the lower unit then you need trim tabs such as Bennett or Lenco.
Tom W Clark posted 07-28-2009 09:09 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
"...if the boat is leaning to one side or the other underway which is generally the result of propeller torque and or poor loading and nothing to do with the trim tab on the lower unit..."

Well, that's a mixture of true and false.

The boat does list due to propeller torque and/or loading. There are also some other reasons a boat might list, like a cross wind, but let's ignore those for now.

It is also propeller torque that causes a motor to "pull," though with modern steering systems it is not a "pull" so much as much greater effort to turn one direction than the other.

The trim tab on the motor is there to correct of steering torque, not a list, but since the two phenomena are so closely related the trim tab will also have an impact on how the boat trims laterally.

A standard rotation motor will pull to starboard because the propeller blades have more grip on their down swing of their arc. This is particularly true when a boat is accelerating and the motor is trimmed down. The effective pitch of the blade is much greater swinging down on the starboard side than on the port side where it is swinging up towards the surface.

The thrust the propeller is generating is thus more powerful on the starboard side that makes the motor want to swing to starboard creating the sensation the steering is pulling to starboard (hard to turn to port).

The trim tab is normally set with its trailing edge to starboard to counteract this force. With it angled this way is also providing some lateral force down low on the motor which will exert twisting force on the boat counteracting the twisting force to port the propeller itself is exerting.

Now, if you have the trim tab set backwards, that is, with the trailing edge to port, you now have both twisting forces compounding each other and that can really make a boat "lean over".

Installing trim tabs would correct the list too, but you would not be solving the problem, you would just treat the symptom. You could just as easily load some lead to starboard, but again that does not deal with the cause of the list.

You don't have to understand or even care about the theory. Just go try it yourself; move your tim tab trailing edge for starboard to port and see what happens. It's an interesting experiment.

highanddry posted 07-28-2009 10:34 PM ET (US)     Profile for highanddry  Send Email to highanddry     
The trim tab adjustment will not correct a list underway. It will correct a pull but not a list. The tab is perfect in fact at only one boat speed and one engine speed and therefore will never be optimal. Therefore, even entertaining the thought that the lower unit tab could correct for listing underway, it would do so at only that one speed. Therefore we can conclude that the ultimate solution to listing would be Lenco or Bennett tabs and to correct engine pull or difficulty to turn the wheel counter to torque we can adjust with the tab, best we can.

I will not split hairs with you, I will just go ahead and tell you that you are wrong as often is the case.

Tom W Clark posted 07-28-2009 11:56 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Well, there you go folks. highanddry has a chip on his shoulder about something. That's too bad.

whaleofatale -- Let us know how it goes this weekend.

Swellmonster posted 08-04-2009 10:28 PM ET (US)     Profile for Swellmonster  Send Email to Swellmonster     
Power steering ie 225 hp doesnt have that little tork tab. My boat doesnt lean
Hmmhh
whaleofatale posted 08-05-2009 12:44 PM ET (US)     Profile for whaleofatale  Send Email to whaleofatale     
Swellmonster I wish I had a 225!

There were a few problems this weekend. The weather was really bad and I knew I would not be out long so I only put in 24 gallons of fuel. When I went to put my motor down it wouldn’t go, bad tilt motor. It has been sticking for a while and I gave up and put a bolt in it and released the bypass screw. I placed the trim tab dead center and the boat was not as hard to turn to port as before but the steering is still tight, SeaStar hydraulics. It still tracked straight but sometimes it felt as thought the steering slipped a tooth but I don’t think it has teeth. The boat still leaned to port at high speed, but not nearly as bad as before. The skimmer transducer was kicking up a two foot rooster tail so I turned it up completely and that helped, we were riding level. The motor was trimmed almost all the way down and I had one third of a tank and the fuel level was a big factor before so I will need to do more testing.

Thanks for everyone's help.

Tom W Clark posted 08-05-2009 05:31 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Once you move the trim tab trailing edge to starboard, it will be even better.

Remember, standard rotation motors that have a trim tab, need to have it set to starboard, counter rotation motors need to have it set to port.

How much angle is what you need to play with but always some degree, not just straight.

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