Severe corrosion on Suzuki 15hp

[FLABOY]

I have had many outboards over my many years,and mostly in salty environments, but I have NEVER experienced the problems I've encountered with my 2017 Suzuki DF15a electric start purchased in July 2017 new. Recently the starter failed and upon examination, the wires at the starting circuit socket/relay ,and one relay pins, had broken off due to corrosion.. The terminals were not sealed , therefore allowing condensation to enter the connections..Electrolysis did the rest.. I contacted Suzuki and was told they DO NOT warranty corrosion problems.. They recommended a new harness at $285 and new relays... Not only is corrosion in the enclosed area (cowling) excessive,but hardware, shifter,lower unit also; some screw heads OK, some adjacent ones oxidized badly..I recently sold a 1967 Evinrude 6hp which was in better condition..BAD quality control and poor material selection definitely evident.. Suzuki 3 year warranty may be useless.. Have others had the same experiences??

[Captain Bill]

I have the manual start model from 2014 and I have a bit of pitting on the leg despite replacing my zincs regularly. Since I am a full time cruiser mostly in salt water I seldom get to flush the engine with fresh water. I have twice had overheating problems from salt deposits in the power head. The first time I had it repaired professionally but the second time I did it myself and discovered that the engine has an internal anode in the head that is not mentioned in the owners manual! It was pretty much gone. If you get a copy of the parts manual you see it listed, but I can not find it mentioned anywhere in the owners manual. Except for the overheating problem caused by the salt deposits I have not had any other issues so far. The motor overall has been much more dependable than the Yamaha that I replaced, but then again it's much newer.

[a64pilot]

Ive had no corrosion, but when I got it, I took the cover off and sprayed everything with Corrosion-X, something I used to do with my bigger outboards too, and I do to my generator and the Yanmar.
Actually I have had corrosion of the fuel hose clamps, they didn’t fail just were rusty so I replaced them with zip ties.

You need the service manual. The anode is shown there, also there are several Utube videos on servicing the thing, that show that anode. I’ve not replaced mine, but if memory serves, it’s not a simple thing to get to, I think you have to remove other components.

What astonishes me is the lack of reports of electronics failure, as dependent as that thing is on electronics, and as complex as it has to be with throttle position sensors etc. I would have expected failures by now.

Bill, when it overheated, what did it do, how did you know it was an overheat?

[Cheechako]

Maybe the way it's setup on that boat it's getting flooded with seawater regularly. ?

[Captain Bill]

Originally Posted by a64pilot

Bill, when it overheated, what did it do, how did you know it was an overheat?

It went into limp home mode, running at low RPM and would do so for about three minutes then shut down. The red warning light was on. It would restart immediately for another three minutes. I had to do this three times to get back to the boat. I should note that both times this has happened I had been on the hard for a month and had not been using the dinghy. The only options were no oil pressure or overheat for the indication, and I checked the oil and it was fine. Could have been an oil pump I suppose. The first time it happened I took it to a shop and had it checked.

I took the thermostat out and it was coated with salt crystals and stuck. The passages behind the thermostat were heavily coated with crystals as well. I took out the anode which is screwed onto a cover. It was pretty much gone and coated with salt as well. Fresh water did not seem to be having much effect on the crystals which are probably best described as precipitates caused by the heating of salt water such as those found in a raw water cooled diesel that runs too hot. These are not just dried salt that will dissolve in water. I used some diluted Ospho in a spray bottle to squirt it down into the passages. It made short work of the deposits. I also used it to clean the thermostat which was not opening. After about a hour soak it was opening at 130. I put it back together and ran it for about an hour, but I was still in a salt water area. A couple of days later I was in the Sassafras river in the northern Chesapeake and gave it a good run in fresh water. I now make it a practice to flush it every time I'm in a marina, but that won't help much when I'm in the Bahamas for six months. Since I now have a 30 gph water maker I'm thinking that once every couple of weeks I'll sacrifice an hours run time and give it a fresh water flush and hope that is enough. I can't see flushing it with fresh water every day.

I sprayed my power head with T9 Boshield to prevent corrosion.

[a64pilot]

I only very rarely flush mine as well, I guess I need to more often.
My bigger outboards, I would flush after every use, even if the boat was still in the water.
I wonder if your was / is running hot, hot enough to precipitate the salt, but not so hot that it trips an alarm?
In other words, I wonder if your thermostat needs replacing?

[Compass790]

Had an older 2hp 2 stroke Suzuki that I had to fibreglass the cylinder water jacket as it corroded. They were known as "Disprins" ( water soluble aspirin) apparently in NZ. Unfortunately I only found that out later.
Since then I've stuck to yamaha in the up to 15hp range with no problems

[dneve]

I have a 7 year old Suzuki 4hp-4cycle which runs well so long as I flush it with fresh water every month and use lots of CRC or WD 40. Corrosion is rampant if you dont stay after all parts of the engine. Also the carb jet will clog if old gas is left in the bowl so run it monthly using Biobor, etc. Grease the steering also.
Not as good as a Yamaha but with care the Suzukis will run for many years.
And yes parts are very expensive also. The motor is in Miami with heat and humidity year around.

[Captain Bill]

Originally Posted by a64pilot

I only very rarely flush mine as well, I guess I need to more often.
My bigger outboards, I would flush after every use, even if the boat was still in the water.
I wonder if your was / is running hot, hot enough to precipitate the salt, but not so hot that it trips an alarm?
In other words, I wonder if your thermostat needs replacing?

I tested on the stove once I had cleaned it off and it opened at 130 which is what was stamped on it. Just because it's open at 130 doesn't mean that the flow is sufficient to keep it below 150 inside the head and if I remember correctly that is the critical temperature. I know some raw water diesels tend to have hot spots in the cooling system where the precipitation can get started, maybe these engines do too. I wish I knew what temperature triggered the alarm. I have an infrared thermometer maybe next time I have it out I'll check the top end for hot spots.

[Macsea]

Have you put any anti-fouling paint on it? ie copper based?
Or any brass screws or bolts?
Are the anodes painted over?
All of these will cause a lot of problems on outboards.

[Mike Banks]

The trouble with saltwater cooled outboards is corrosion. Sooner or later it gets to them all.

Air cooled is noisier but better--just wear ear muffs.

I stripped my Yamaha 3.5 and found it corroded to the extent that the outlet hole was blocked. Cleaned it all out and noticed the varnish stuff they use to keep the seawater off the alloy was bloody USELESS. Very thinly applied and had disappeared from most surfaces.

Carefully scraped it all out and freshwater blasted it and dried it thoroughly using hot air and clear alcohol--then used epoxy water tank resin to coat everything the water contacts, including the surfaces where gaskets will fit later. So far no further problems--but I have not used it much since then.

[GordMay]

Greetings and welcome aboard the CF, FLABOY.

[ranger58sb]

I've recently discovered the over-heating problem. We only have about 17 hours on the outboard, and it went into limp mode as I brought it from ramp to mother ship. The whole cylinder head was clogged with salt; the techs had to chip it out... huge $$$ to learn that...

Turns out part of the problem seems to be that running fresh water through the flushing port, engine off, apparently doesn't at all route fresh water up around the cylinder head. Gotta to that with the muffs, engine running, so the water pump circulates flush water everywhere.
<sigh>...

-Chris

[thomm225]

Originally Posted by ranger42c

I've recently discovered the over-heating problem. We only have about 17 hours on the outboard, and it went into limp mode as I brought it from ramp to mother ship. The whole cylinder head was clogged with salt; the techs had to chip it out... huge $$$ to learn that...

Turns out part of the problem seems to be that running fresh water through the flushing port, engine off, apparently doesn't at all route fresh water up around the cylinder head. Gotta to that with the muffs, engine running, so the water pump circulates flush water everywhere.
<sigh>...

-Chris

Some of the newer engines like my 2011 Mercury 5 hp do not have the water inlet holes on the sides so muffs won't help. About the only way is with a bucket which is what I use when in the yard

I have lots of rust also on bolts and hose clamps but no problems with salt water stopping the engine yet

It did over heat one time when I tried to get 3 years out of an impeller though and I've had to clean my carburetor once for an idling problem which I was able to do without removing it

I've flushed my engine maybe 10X in 7 years but start it several times a week in season plus use it on the weekend. And I run it at least once every two weeks in Winter if the temp is above freezing

My zinc though was totally covered with some dark material and may not have been working properly. I changed it yesterday and it took a long time to get the old one off. it was about 2/3rds used up

[mikedefieslife]

Originally Posted by a64pilot

What astonishes me is the lack of reports of electronics failure, as dependent as that thing is on electronics, and as complex as it has to be with throttle position sensors etc. I would have expected failures by now.

Electronics tend to be much more reliable than mechanical items. They don't really wear. Wires may get snagged or broken though.