DF150 Trim tab / sacrificial anode / torque tab

[rick341]

The tab on my 2017 DF150 is painted from the factory. The trim tabs on very other outboard I've ever owned were unpainted zinc and served as sacrificial anodes so I'm just a little concerned about this one being painted. After searching the forum, I found some posts stating they should be painted and aren't anodes and others stating they are... so now I'm confused and looking for an answer. I can't find a sacrificial anode trim tab listed in the parts list so I'm guessing it's not sacrificial and should be painted. Now I'm wondering if the tab is painted zinc and if the paint were removed, would it help reduce corrosion or do I just worry too much?
Rick

[Harper]

It's not an anode, just a trim tab. You have the two anodes just above the anti-ventilation plate, one each side. Also one at the bottom of the swivel bracket, a round button-type (same type as the internals), and the large anode at the bottom of the clamp bracket. Those are the only external anodes. You also have five internal anodes in the powerhead (three in the cylinder head, two in the block) that require your annual attention.

[rick341]

Thanks.. I didn't know about the ones in the power head or the block. Are they user replaceable? I'll have to do some searching and take a look at those. Is the trim tab aluminum, steel or zinc? Would it help any to strip the paint off of it? It's not big enough to be effective as a rudder or to adjust any degree of torque.

[Harper]

Don't strip the paint off the trim tab! It IS large enough to do what it's designed to do. If you don't believe that, just loosen the bolt and turn it two or three notches in one direction or the other. I repeat, it is NOT an anode. It's most likely made of the same metal as the rest of the lower unit. The internal anodes are easily accessible to you, and you should inspect them at least annually, brush off the salts that build up as a result of the sacrificial chemical reaction that protects your power head, and replace them when they are 2/3 gone. If you care about your investment, my advice to you would be to invest in a Suzuki service manual for your 2017 DF150. Don't go cheap. None of the other generic manuals will cover your outboard as well as the official manual. All your periodic maintenance procedures are covered in the front of the manual.

[artdf175]

First suggestion would buy a copy of the Suzuki Service Manual - this will answer most of the questions
Second - if it is factory painted - it is supposed to be painted
And since it is located where it is, in the direct path of the prop wash, it provides enough offset to counter the torgue created by the prop.
Art

[Moonlighter]

Thanks.. I didn't know about the ones in the power head or the block. Are they user replaceable? I'll have to do some searching and take a look at those. Is the trim tab aluminum, steel or zinc? Would it help any to strip the paint off of it? It's not big enough to be effective as a rudder or to adjust any degree of torque.

Dont strip the paint off. NO!!

The trim tab isnt an anode, and it IS certainly large enough to make a noticeable difference to steering torque if adjusted.

You are being fairly presumptuous making a comment that suggests that the design engineers at Suzuki dont know what they are doing!! I can assure you, they most certainly do!

There is a large flat anode under the engine bracket, at the bottom, that provides corrosion protection to the engine’s external parts.

The internal anodes in the engine are of course replaceable, and should be checked every 100hrs or 12 months. If you buy the Suzuki service kits for your motor, they come as part of the kit.

see:
https://www.brownspoint.com/store/pc...-165p74594.htm

[rick341]

Thanks again. The service manual is a great idea. I'll try to find one online tonight. As for the tab, I understand that they are intended to counter act torque but this is the first one I've owned that doesn't also serve as a sacrificial anode. I've adjusted the tab both left and right several holes and it may be my steering, but it makes absolutely no difference in handling on my boat so I just set it straight to have less drag. Since it's not zinc, I won't remove the paint. I was just wondering if replacing it with a zinc tab (if there's one that will fit) would provide any additional corrosion protection.

and for the record I was asking for advice and information in my question. I don't consider that presumptuous and I made no comment suggesting that the design engineers at Suzuki or anyone else didn't know what they were doing.

[Moonlighter]

You said, and I quote: ““It's not big enough to be effective as a rudder or to adjust any degree of torque.””

Perhaps presumptious was too strong a word, but that seemed like a fairly bold statement to me! LOL lets leave it at that, no offence intended.

If you have hydraulic steering, then the hydraulic steering pump has anti-feedback valves that almost eliminate steering torque feedback, so you wont notice changes in tab positioning nearly as much as with cable steering. Set it straight, will be fine.

Yes, other manufacturers use the tab for dual purpose as both a steering torque adjustment device and as an anode - I suspect Suzuki saw the folly in this approach, because as the anode wears away, the function as a steering torque adjuster is ievitably compromised!

[rick341]

Makes sense to me. Now if someone would be kind enough to point me in the direction of the right 2017 DF150 service manual.. I'm finding several different ones at various prices online.

[Harper]

Rick, are you boating in salt water or fresh?

[Moonlighter]

Find your engine serial number and model code, then have a look in the documents listed in this sticky thread for the part number for your engines service manual, then copy and paste that part number into the search bar in the “buy Suzuki parts” link on this forum.

http://www.suzukioutboardforum.com/f...ervice-manuals

[rick341]

Rick, are you boating in salt water or fresh?

Salt water Mike

[Harper]

Okay, just making sure. The 2 anodes on the lower unit, the small rectangular ones, are zinc, the large rectangular anode on the clamp bracket is also zinc. The small (1" dia.) anode on the front of the swivel bracket and all 5 internal anodes are all aluminum anodes. If you ever transition to mostly freshwater boating, the 3 zinc anodes should be swapped to magnesium. Research has indicated that aluminum anodes are more effective than zinc at preventing galvanic corrosion in salt water. So if you can find them, you can use all alumiinum anodes in salt or brackish water.