trim tabs

[bluebikemike]

Does anybody have any knowledge on trim tabs? Mine seem to be ok but if I go faster than about 4000rpm they seem to move and make the boat very unstable. Just had new lines and pump installed maybe the shop didn't bleed it? Any ideas

 

[wolf]

Once they are set they shouldnt move at all thats why they are hydrolic, now for the stupid obviuos did they put fluid in them???
they do need to be loaded up if they havent all you do is undo the cap to the pump put an absorbant rag or towel under it and just move them up and down one at a time there may be some overflow that why the towel.


Good luck Wolf

 

[bluebikemike]

Hi Wolf, The res is full of oil and no leaks maybe it just takes a while for the air to get out of system. I cycled them up and down probably 20 times will know when I stick back it water.

Thanks Mike

 

[HALILLAMA]

Be Careful! At 4000 rpm too much on one side or the other can force your V of the bow in and cause the boat to veer port or stbd easily.[:0] When you are on a plane it should only need enough to stop porpoising. Do you have racing style or joystick controls? Did you try trimming the engine after a small trimtab adj? What kind of boat and power?

 

[MyEscape]

There seems to be a real misconseption with trim tabs. In a proper balanced boat (Port to STBD and Bow to Stern) trim tabs should only serve two purposes of balancing the boat when loaded with a difference of weight or to pull the bow down if you want or have to in rough weather.

If when planning you are chine walking on your trim tabs you have an over powered boat.

Most trim should be done with the motor unless you have some big fishing buddies on one side of the boat then trim may become more important.

Always fully pull up your trim tabs every time you fire up your motor then you know there up!

It takes alot to bleed the air out of lines up down and repeat, repeat, repeat !!!!!!!

Cheers ME

 

[bluebikemike]

I think that it's racing style, 2 buttons. The boat veers to the side once I get past 4000rpm the boat is a 22" whaler revenge with a 200 kicker on it. Hopefully will try boat out on weekend see if bleeding helps. Thanks for advice. Mike

quote:Originally posted by HALILLAMA

Be Careful! At 4000 rpm too much on one side or the other can force your V of the bow in and cause the boat to veer port or stbd easily.[:0] When you are on a plane it should only need enough to stop porpoising. Do you have racing style or joystick controls? Did you try trimming the engine after a small trimtab adj? What kind of boat and power?

 

[battaglino]

I agree with HALILLAMA it sounds like a motor trim problem not a trim tab once you are up on a plan they are just used to level the boat. Make sure your outboard or outdrive is trimed properly. I know when I first starting boat I couldn't figure out why boat was pulling sharply when someone asked me it I had trimmed the boat properly. I had to ask him what was the trim? I felt pretty silly but alway willing to learn and it solved the problem. Hope you figure it out.

 

[bluebikemike]

I have played around with the trim doesn't seem to help. I just had a friend of mine look at it a ex marine mech he said that the motor was too low and should be raised about a inch and a half the fin on the leg should be just above the bottom of boat I guess it couldn't hurt to try it, will have to eat wheeties to lift motor.

 

[MyEscape]

Not to stir things up but the plate should be paralell with the bottom of your hull not above it or below it and that would not cause your boat to vere off one way or another although it would make steering very touchy.

How ever if you have lots of power and the motor is trimmed up to high your boat will start to chine walk and feel very unstable because very little of the boat is touching the water. Try trimming the motor starting with it trimmed right in then while picking up speed slowly trim it out and you will find a sweet spot of rpm vs speed vs handling.

JMHO
Cheers ME

 

[bluebikemike]

Had the boat out on sunday, raised the motor about 2" on the transom runs like a dream, trimed it out to 42mph with 5 people in boat stable as a rock, I guess it wasn't the trim tabs. Thanks for the help.

Mike