How much trim do I need

[scottnjay]

I have been reading a lot on this board about how to drive a boat since I am new (this place is awesome). My boat appeared to suffer from bow steer and the trim anode in the wrong position. I finally got it straighted out by trimming pretty high at WOT but when I turn I have to trim back down or I think the motor is going to blow. Is this normal? My friends don't have to mess with it, but they have smaller boats. I have a 98 fisher deep-v and a 120 force OB. I have been told I will need a new prop due to elevation change from MN to MT. Is this part of the culprit? Thanks

 

[Chris1956]

Re: How much trim do I need

ScottnJay, Bow steer is caused by the bow of the boat influencing the direction. This only occurs when the bow is driven down into the water due to incorrect(too much down) tilt of the outboard. It is probably not your problem. The pulling of the steering wheel (I think this is your problem) is influenced by the tilt of the motor and the position of the zinc anode (aka trim tab). With the motor in normal tilt position, at cruising speed, If the boat's steering wheel pulls right, turn the anode CCW (viewed from above). If it pulls left, turn the anode CW.<br /><br />You will need another prop (with a smaller pitch) if you cannot achieve the max RPM listed by the manufacturer at wide open throttle(WOT). if you exceed the max RPM, get a new prop with a greater pitch.

 

[quantumleap]

Re: How much trim do I need

edit.

 

[Jdeagro]

Re: How much trim do I need

Are you running a hydrofoil on the motor?

 

[salty87]

Re: How much trim do I need

i bet this thread is getting a lot of views!<br /><br />how much trim can ya get?

 

[ae708]

Re: How much trim do I need

Salty I was on the same track as you lolol

 

[scottnjay]

Re: How much trim do I need

I don't have a hydrofoil. I just seem to track better in the water when I am trimmed up almost as high as I can get without the prop loosing its grip. I have to change the impellor this weekend then I will try to use less trim to see what the impact is. I got the steering pressue pretty even either way so I think the trim anode is in the right spot now.

 

[roscoe]

Re: How much trim do I need

You may need to rejet the carbs, using smaller jets, to compensate for the elevation and thinner air.<br />In the end, you will probably need to drop the prop pitch to get enough power and to achieve proper rpm.