# Steam from 15 hp Suzuki Four Stroke



## Brett (Jul 16, 2008)

Sounds like you caught a plastic bag on the lower unit.
Blocked the intake until you dropped back to idle then washed off.
Been there, done that...had to replace my impeller and re-torque the heads.
Hope yours hasn't done that much damage.

:'(


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## tfl813 (Jan 1, 2012)

I did see alot more debris than usual in the water, including a few plastic bags... :'(  

If it's the impeller, I think I can handle the repair myself.  But what's re-torquing the heads?


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## Brett (Jul 16, 2008)

Many bad things can happen when a block overheats.
Worst scenario is the engine seizes, things snap inside, block is totalled.
If you're lucky, engine didn't get hot enough to do mechanical damage.
Still, it probably got hot enough so that the metal components increased in size,
and compressed the gaskets between them enough that the bolts will need to be tightened
in order to maintain seal between the block and the heads. The fasteners have to be tightened
in a certain sequence and to a specific measurement (torque).


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## tfl813 (Jan 1, 2012)

Oh boy.  Re-torquing the heads sounds out of my league.  Did you do it yourself or go to a mechanic?


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## Brett (Jul 16, 2008)

I learned how to work on outboards by going through the same problems as you are.
Didn't have cash to pay for parts and repairs, so I learned to do repairs.
The most important part needed is the Suzuki factory (OEM) shop manual.
With the manual in hand, all repairs and specifications are thoroughly explained
and displayed with close up images, step by step instructions. If you don't feel
confident in your own mechanical skills, take it to a good outboard mechanic.


I'm honest with myself about my skill level...see my tagline below...


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## tfl813 (Jan 1, 2012)

I just ordered the manual off of amazon...$20.  I'm actually a little excited to work on the engine, but I'm sure it will lose its allure as so as I realize what I got myself into. Was it a difficult repair for you and was it challenging to get to the bolts?


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## Brett (Jul 16, 2008)

Working on outboards is another way to spend a weekend.
Hopefully a cold and nasty one so you don't feel like you're missing out.
I enjoy it, kind of like a jigsaw puzzle that you can actually use when complete.
Every time something breaks, I learn something new. Never found a problem
that couldn't be solved using the OEM manual, common sense, and a few specialty tools.
Head bolts are usually easy to access, the manual will show you how and where.


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## tfl813 (Jan 1, 2012)

Thanks for all the advice, I really appreciate it!


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## DuckNut (Apr 3, 2009)

JohnnyBoy, I get steam several times a year when hunting.

At idle no very little steam that you don't notice it, at speed lots of steam.

Every single time the culprit was the inmpeller. Most of the time it is one or two fins broke off. A couple times, somehow one of the fins somehow gets spun the wrong way.

If your motor was running and is still able to run, replace the impeller and give it a go.

Bret's advice on a manual is a must - MUST refers to a shop manual, not Chiltons.


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## levip (Dec 4, 2010)

AGREED those chiltons and clymer and other various generic manuals are only good for toilet paper and even then only in a pinch.... 
make SURE you bought one FROM suzuki or off thebay cause if it was printed by THEM its useless go to the nearest dealer they might have a used one theyll let you have since this engine is a bit older


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## levip (Dec 4, 2010)

youve got mail btw


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## tfl813 (Jan 1, 2012)

Since my engine does run and didn't seize up, I'll just replace the impeller and go from there, as Ducknut said. 

...Well the manual I ordered was clymer's, but thankfully it hasn't shipped yet so that's no big deal to get a refund.  I got your message Levi and I'll be ordering that Suzuki one today.


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## tfl813 (Jan 1, 2012)

I talked today with a friend of mine and he suggested that I just start up the engine because it may have simply overheated from something blocking the intake.  Since it was running for less than a minute after the blockage occurred he said that there's a good chance the engine suffered no damage.  

So today I got out the trash can and started her up, and she started up first pull, no steam, no weak pee stream.  I left her running for about 15 minutes at half throttle and she ran perfectly normal, no overheating.  I'm going to test her out on the river this weekend, but I'll stick close to the ramp just in case something happens and I have to troll back.  Problem solved?


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## Brett (Jul 16, 2008)

I'd still replace the impeller assembly and re-torque the heads.


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## DuckNut (Apr 3, 2009)

I would replace the impeller - but would not touch the head bolts at this time.

edit: with the lower unit off you can ensure that there is no obstructions.


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## Creek Runner (Sep 1, 2011)

Just to throw a monkey wrench out there, just because an engine produces steam/condensation doesn't mean it is overheating. The normal range of an outboard is around 170-180 degrees ( some cooler some hotter) If your thermostat is lets say 145 degrees which is common, the water temp has to be hotter than 145 to open, on a cool day of less than let's say 60 degrees your going to get some steam/condensation. Not saying your motor didn't over heat just wanted to let other people know who read the post and see steam doesn't mean your motor is overheating. 

However a water pump impeller is very cheap insurance, so any time doubt is there replace it. So as Brett said still replace it!!!


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## Creek Runner (Sep 1, 2011)

> I would replace the impeller - *but would not touch the head bolts at this time.*
> edit: with the lower unit off you can ensure that there is no obstructions.


WHY? There is no down fall to checking the torque of the head bolts, it's routine maintenance that is free to do!


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## tfl813 (Jan 1, 2012)

Just a little update on the whole situation.  I took it out Sunday and she ran fine, except when I was going fast.  I would go WOT for a few minutes and then the pee would just become weaker, so I would put it back to neutral and then it would be fine.  It just kept on doing this, so I just turned around and went back at about half throttle and had no problems.  My top speed wasn't affected.  I'll just go ahead and replace the impeller.  I still don't know why it only happens at full throttle, and why it takes a few minutes for the pee become weak.  The river was also very dirty with leaves and bags, but at this point I'm just going to open it up and see what's wrong.

Btw, what will happen if the heads are loose, will I lose compression? 

Thanks for all these replies too!


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## Brett (Jul 16, 2008)

Lose compression, burn a gasket, bleed exhaust into water jacket
pull water into cylinder, bleed water into the bolt threads and cause corrosion.
Torquing only takes a few minutes when you know how. Easy to learn.


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## DuckNut (Apr 3, 2009)

> WHY? There is no down fall to checking the torque of the head bolts, it's routine maintenance that is free to do!


Modulus of elasticity and friction.

Here's the downside: as I would put a wrench on the bolts and turn the bolts a miracle would happen. The bolts turn easily and therefore must be loose - snap!

I personally am a firm believer of the if it's not broken theorum. I am equipped to handle torquing a bolt - I am not equipped to remove a snapped off bolt. You might be but I am not. 

Just an opinion CR and your other comment about steam is spot on.


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## tfl813 (Jan 1, 2012)

*Re: Steam from 15 hp Suzuki Four Stroke, WITH PICTURES!!*

Well after ordering the part and having enough time on my hands I decided to replace the impeller...and here's what I found.  I looks like someone lit a fire inside my lower unit.  The old impeller looked fine, nothing was wrong with it, so the problem is somewhere else, but I'm not sure what. 

Everything Is completely covered in soot.  I'm not sure if I will have to replace more than the impeller, have a look.  There's also corrosion in the upper and lower unit, not sure if it's normal?










The seal is hard from all the heat, so I think it needs replacing. 










All that black stuff on the right is soot, not paint. 










The bottom left is what the upper right should look like.  










Not sure if anything is wrong here besides the soot?










Here are the gaskets, I'm replacing both of these, but they were like stuck to together and I had to rip them apart?










And here's the new Impeller, nothing was wrong with the old one though...










Here's the upper...










Here's a gasket on there that appears to be coming off, should I replace it?











I know it's a lot of pictures, but I think everyone on this forum loves looking at boat related pictures.


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## Brett (Jul 16, 2008)

Looks like a normal exhaust housing to me.
Expect to find soot, those are carbon deposits from burnt fuel and oil.
Same deposits as found in the exhaust pipe of your car.
The rear of the lower unit is where the exhaust feeds down to exit
through the hub of the prop into the vacuum created behind the prop.
So finding soot there is normal.










You've already got the lower unit apart...that's the hard part.
If it was my outboard, seeing the cooked condition of the upper seal,
I'd replace the entire water pump housing and assembly, including the loose gaskets.
Look carefully into the threaded mount holes in the photo...see the white crud in there?
That's future trouble heading your way. The aluminum is breaking down due to
contact with the steel machine screws. Salt water, heat and galvanic corrosion are the culprits.
I use an OMC sealant on the threads to slow that process down.

http://www.google.com/products/catalog?hl=en&q=OMC+Gasket+Sealing+Compound+4+oz&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1280&bih=579&um=1&ie=UTF-8&tbm=shop&cid=16798479558975995185&sa=X&ei=0hRQT7rdF9CUtwe1xvmzDQ&ved=0CGUQ8wIwAg


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## tfl813 (Jan 1, 2012)

That's good to hear, but do you know what could be causing the problem I was having, was it the seal you think?


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## Brett (Jul 16, 2008)

Losing water pressure can be caused by a multitude of problems.
Partially blocked passageway, corroded thermostat, split seals, bad/blocked poppet valve,
blown gasket, cracked/corroded water tube/neck, bad o-ring, worn housing,
warped base plate, worn impeller (both the tips and top/bottom), impeller separated from bushing,
sheared impeller key, blocked intake are all problems I've had to deal with over the years.

An impeller can look great, but if it's been run in silty or gritty conditions, the tips and top/bottom edges
can be abraded enough that the impeller loses contact with the insides of the impeller housing.
Without a tight seal to the housing, the impeller no longer functions efficiently.


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## tfl813 (Jan 1, 2012)

Thanks for all this good info, that's a big list!  I'll start out with the seal, wear plate, gasket, key, and impeller, hopefully it's one of those.


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## tfl813 (Jan 1, 2012)

For the installation of the gear case gasket and the gasket in the water pump do I need any adhesive?


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## Brett (Jul 16, 2008)

Follow the instructions and torquing sequence as shown in the Suzuki shop manual.
If you are attempting this without the OEM shop manual, you're braver than I am.


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## tfl813 (Jan 1, 2012)

The manual I have sent me on a wild goose chase of (see fig.)  and "refer to", but I found what I needed.


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