Are trim tabs supposed to be above water?

redeye1962

Petty Officer 1st Class
Joined
Jul 6, 2008
Messages
319
We took our boat out for the first time in a long time. I put some tabs on the 90hp outboard engine. When trimming the boat I noticed the bow was grabbing downward so I lifted the engine a bit to raise the bow (still getting the hang of the trimming and tabs) and it sounded like the prop was hitting outside the water and the trim tabs were above water as well. The engine was not raised that high but lowered it down and the sound went away.

I was just wondering if these tabs that attach to the lower unit are supposed to be riding above or below water.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Are trim tabs supposed to be above water?

The A/V plate should be parallel to the water when on plane; if the A/V plate is still below the surface when on plane,the hydrofoils will produce significant drag. Hydrofoils will produce significant drag on turns anyway .
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Are trim tabs supposed to be above water?

get rid of the hydrofoil, and get a set of smart tabs.
 

redeye1962

Petty Officer 1st Class
Joined
Jul 6, 2008
Messages
319
Re: Are trim tabs supposed to be above water?

get rid of the hydrofoil, and get a set of smart tabs.

What!!!! and get rid of the cool looking Hydrofoil? I have done some research on the smart tabs and I like what I see. What do I do with the holes I put on the lower unit for the hydrofoil?
 

OnTheWaterNow

Petty Officer 1st Class
Joined
Mar 18, 2009
Messages
210
Re: Are trim tabs supposed to be above water?

fil them in sand them repaint I used some liqiud aluminum sets up fast sanded them removed prop anode trim tab primered and painted and clear coated the lower unit looks brand new this is a link to good paint primer clear coat

http://www.wholesalemarine.com/p/MOE-025425/ primer clear coat is at bottom of page
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Are trim tabs supposed to be above water?

Place masking tape on the underside of the AV plate. Fill the holes with epoxy. Sand and paint (if the dots bother you).
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: Are trim tabs supposed to be above water?

shouldn't the cavitation plate be even with the keel?:confused:
 
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