2015 Suzuki Rusting?!

Tripp Halbert

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Jul 30, 2013
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Hello everyone, I bought a new 2015 Suzuki DF115A last year in June for my 175 searay. It runs smoother, quieter, and stronger than any outboard ive ever had. At about 50 hours I took it to the dealer because it had a couple rusted bolts on top of the block (6 year warranty). They changed them out at no charge along with some sensor that rusted as well and informed me I wasn't cleaning under the cowl well enough.:facepalm: It now has 150 hours and I have more components rusting again already!? Coil mounts, bottom of flywheel, two sensors heavily on starboard, 2 head bolts, the list goes on. It seems the problem is on both sides of the motor but mostly the port side where this special intake vent is which i suspect may be the culprit. I have nothing on my transom that spits water on the cowl. I don't take it offshore so no waves have crashed over the cowl. I have no idea how else I could be taking in this much salt under the cowl? The flywheel seems to be the primary area where salt gets to and is then distributed throughout the area. Could this engine be seeping the salt water internally?

Does anyone have this engine and/or have similar problems with newer Suzukis? Any ideas on how to clean this thing better; I have read that you can light rinse the engine w/o cowl when cold? I have had plenty of pre-2000 2 strokes that I never had to clean under cowl once and never seen any salt buildup on the engine block/components, what is going on here?! I flush the motor on muffs every single time I take it out and clean under the cowl every 3-4 trips. Please help, I don't want $11,000 to rust away before 300 hrs.​

Follow link attached to my facebook for pictures and descriptions. Thank you in advance for any help/advice, I will be taking it back to dealer but I know what they will say again.
 
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Chris1956

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Mar 25, 2004
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You might check to see that you do not have a water leak under the cowling. If no water leak, that is a lot of rust in a short time....
 

Tripp Halbert

Petty Officer 1st Class
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Jul 30, 2013
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Yea I agree Chris. Do you mean like a water leak from below the cowling at the waterline or on top from overspray/splashes, etc.?

I tried water testing the cowling with a hose and some water is able to migrate behind that fancy intake grill. id imagine when it is running and sucking air that this effect would magnify.
 

Sea Rider

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Sep 20, 2008
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Once you find the culprit and fixed the problem. Get a medium size painting brush, spray W40 or any rust inhibitor and paint the whole under cowl parts, apply/paint as needed, reapply once in a while. Just need a small amount of product not a shower direct from can.

Happy Boating
 

Tripp Halbert

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Jul 30, 2013
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Thanks Searider, I like the idea of the paint brush, that's a great technique to get into the hard to reach areas!

So I guess the general consensus here is that something is allowing moisture/salt directly into the cowl compartment...hmmm....any good troubleshooting ideas?
 

dpoff

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Nov 27, 2004
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When I took my new at the time 2011 DF150 in for my 20 hr check up, the Suzuki repair location recommended spraying the engine with CRC 6-56 spray 2-3 times a year. Been doing that since new, and....it still looks new! And it`s not a messy product at all.
 
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Sea Rider

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Is lower pan (where powerhead rests) perfectly sealed ? Lower pan has small breathing holes, salt water, moisture can get in through them and eventually rust internal parts . Usually seal with silicone all my OB's pan holes and avoid salt water, moisture intrusion. Apply W40 paint/brush from time to time to look mint cond. Is cowl's lower rubber seal sealing well against lower pan edge ?

Happy Boating
 

Tripp Halbert

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Dpoff - I spray a marine engine sealer on my engine after every time I clean her up. I'm still seeing corrosion in spots I for sure sprayed down liberally. Thanks for the input.

SeaRider - that is a good question and I haven't checked this yet. I highly suspect its possible because of how the midsection is two plastic decorative cover panels that probably don't seal very well. When I have 6-8 people total (max capacity) in my boat the engine sits low enough to where my telltale is below the water line so I'm sure the water line is above the seal/seals at this point.

​Perhaps I should strap the boat to the trailer and drop it in as much as possible at the ramp to recreate this effect and see if water flows in at all???
 

Sea Rider

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When heavy passenger loaded, do you have unwanted back splashes against transom ? if so, water could get in through mentioned holes if happen to have ones, through cowl's lower rubber seal, decorative covers, whichever is causing issues.

Happy Boating
 

Tripp Halbert

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Jul 30, 2013
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No honestly I never have much backsplash over but the waterline definitely gets close to the mentioned holes when I'm loaded. If I have any of those holes, is it okay to plug them? Do they just basically serve as drains for the cowling?
 

Sea Rider

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Would say that actually are pan water drains when rinsing pan with fresh water. Tape them, if no water/moisture intrusion, there's your culprit.

Happy Boating
 

w2much

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Jun 22, 2005
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Are you over the weight capacity? As long as that telltale is underwater I suspect you will have issues. Water will come up the lower cowl as it is not a perfect seal .
 
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