Trim tab concerns

[pstephens46]

I had to buy a trim tab locally. Snapped the old one trying to torque to specified amount. Not gonna make that mistake again.

The old one was traditional zinc construction. Heavy.
West Marine had nothing but aluminum. Very lightweight.
Marine supply store had oem Yamaha tab. Medium weight. Looks like some sort of alloy. This is the one I purchased.

Tou could see the old zinc slowly deteriorate trip after trip. It would develop pits. I assumed it was protecting the motor.

5-6 trips on the new one and nothing. Not one tiny pit.

Anybody else use Yam oem tabs?

[scofflaw]

You have a small trailer boat ?

[TownsendsFJR1300]

I still have the ORIGINAL Yamaha trim tab.

Still looks new....

Now the large one that bolts to the bottom of the mounting bracket, I'll pull that probably once a year and hit it with a wire brush (attached to a drill) to clean off the pitting..

The boat does NOT sit in the water when stored...

[pstephens46]

You have a small trailer boat ?

20ft fiberglass on trailer, saltwater use

Trim tab lasts normally about 1 1/2 years.

[scofflaw]

I got something similar in Fla....use it about 4 hours a day. In the 3 years I've used the boat I see very little wear. Up North with an I/o setup, slipped for 6 months, they need to be changed out yearly

[pstephens46]

My concern is that if it is not eroding, it is not protecting anything.

Meter shows continuity between tab and lower unit.

[fairdeal]

I had to buy a trim tab locally. Snapped the old one trying to torque to specified amount.

ha I've done that -
Had one break off "later" - another as I was turning the wrench.
the number in the SM is nuts - now I just do it by "feel"

(on my to-do list is to buy a longer bolt - then I will drill & tap the anode to the full depth of the casting)

I used zinc the first few times I changed it -
by then had learned of the MIL-A-24779 "Aluminum" and I've been using that -
but "aftermarket" not Yamaha branded.

The story from the anode experts is that "Aluminum" lasts longer than zinc -
(in addition to providing higher voltage of protection

I've seen it described as:
if a zinc anode lasted 100 days, the same size/shape aluminum anode would last between 130 and 150 days.

Here's what my first zinc anode looked like when I removed it after 470 hours