# Evinrude 15hp OB Motor smoking



## Birdface (Jul 24, 2006)

Hey everyone,

I'm on the verge of spending $1,200 just for sanity's sake. And, when you spent $3000 for the purchase of the boat that's a significant investment.

I have a Evinrude 15hp 2 stroke outboard, the PO tells me it was "rebuilt" in 1986 but he doesn't know the actual year of the motor.

Anyway- it's run pretty consistently and without much trouble for three years. I've had some fuel line/air/coupling issues but those have been resolved with a new tank, connectors and hose.

This year, I feel like the motor has been smoking more and more. It's a white smoke with "normal" smell, but on watching neighbor's boats I'm realizing I'm smoking much more significantly than other 2 strokes in my harbor.

I normally mix 2.5 oz of oil per gallon of fuel. I know a rich mixture will cause smoke, is this a high ratio?

Today we refilled with 2 gallons and I threw 5oz of oil in and then we took a spin on outboard only. The smoke seemed worse than ever... so we moored and I took a closer look. My water pump seems to be working fine, I have a steady and strong water exhaust coming off the motor. But I noticed today for the first time that out of my smoking exhaust there is also some water spray. I felt the water and it was warm to the touch....

I have probably three or four more sails in me this year before the yard can take a closer look while they winterize the outboard. But my next sail is with my father and Aunt, both of which aren't sailors and I need to know my motor is sound and not an issue.

I'm more of a newbie with outboards than sailboats... so that's a bad sign, but I guess I'm just writing to see if there's anything significant to worry about, an easy fix or test to run, or just to have my mind put at ease.

I think my overall plan is to put this 1986 on a stand in my basement, buy a 2005 4 stroke or newer and use my 1986 as a learning tool/project motor. But that can't happen in the next few weeks.

Any comments/suggestions are welcome.


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## Freesail99 (Feb 13, 2006)

> I think my overall plan is to put this 1986 on a stand in my basement, buy a 2005 4 stroke or newer and use my 1986 as a learning tool/project motor. But that can't happen in the next few weeks.


Sounds like a good plan. It sounds like you have a 30 year old outboard motor.


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## jgeissinger (Feb 25, 2002)

*Evinrude 15*

Actually, your oil/fuel ratio is just about right at 50:1, where it is supposed to be. When you say you have warm water coming out, do you mean in a steady stream from the "pee hole" or just spitting out the exhaust? Take the cowling off after you have run it a little while and see if you can touch the cylinder head. If it is too hot to even briefly touch, that's not good. I am concerned that the smoke is white, which is very often an indicator that it is part steam. It could be a water pump, a thermostat, or something else equally simple.Don't give up on the motor. They will run a very long time with minimal maintenance, and you can do a lot of work yourself.


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## Birdface (Jul 24, 2006)

JGeissinger,

This is a common piece of advice I get from people "in the know". Don't give up on the motor... I'm a computer engineer but I don't know the first thing about outboard maintenance. So even the smaller repairs feel somewhat risky for me.

I have a steady stream from the pee hole, it's generally been cool water coming out. I've had to clear that from time to time with a small piece of wire but it's running well now.

From the exhaust I have the warm spitting/spray coming out and white smoke.


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## jgeissinger (Feb 25, 2002)

*Evinrude 15*

Well I will have to admit that it beats me. If the pee hole is a steady stream of cool to warm water, and it runs ok, there probably isn't anything fatally wrong. Just for my own curiosity I will run this by a real Johnson/Evinrude expert that I know and see if he has any bright ideas. I'll let you know what I find out.


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## sailingdog (Mar 19, 2006)

Could the cooling passages of the engine have a pinhole leak???


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## Birdface (Jul 24, 2006)

So moisture in the exhaust (warm misting spray) is a problem to worry about then, I'm assuming?

I have a second tank of gas, I'm thinking of mixing it extremely lean and using it to see if the smoking persists. 

Thanks for checking things out with your Evinrude tech, I do appreciate 2 stroke motors, and I understand they're near impossible to find now. 

I also wouldn't mind avoiding the $1200 bill for a 9.9hp 4 stroke. I just took a similar financial hit on my rudder re-fab.

Thanks guys,
-M


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## Birdface (Jul 24, 2006)

Just a follow-up from research, it seems like most people say white smoke is water related, but a number of people say oil can cause white smoke too.

One post mentioned the seal on the clutch end of the crankshaft leaking oil causing the problem.

Still confused though due to the water spray from the exhaust.

Others said there could be water leaking into the combustion chamber. The worst said cracked gasket or similar allowing water from cooling system in.

Could simply be bad gas too I guess? Empty somewhere(?), clean and refill?


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## timebandit (Sep 18, 2002)

More smoke---
My two stroke call for 100:1 (1987) Yahama, so I will show less smoke.

All two stroke motors will show more smoke when you first start them up. It is left over oil suck to the engine walls from when the motor cooled and the gas evaporated.

Are you sure the exhaust is commming from the pee hole or from and exhaust hole just under and centered on the bottom of the powerhead. It seems that when at and idle in nuetral there is not enuff suction at the prop to pull the exhaust through the prop under water and it is designed to exit through this hole. The pee hole is just an indicator that water is flowing--most of it exits underwater, cooling the exhaust.

You might try changing you oil brand, check your plugs, and run fresh gas.

I don't think you have a problem at all.

Rick


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## lbdavis (Apr 23, 2007)

Birdface,

I'll cast another vote for not giving up on this engine. You are likely to still get more years out of your ?30? year old 15hp, than out of a new four stroke. New four strokes run great, for about 4 or five years. 

As long as you haven't damaged cylinders or anything, you will run that old 2 stroke for a loooooong time for minimal maintenance. 

One thing I would research is your oil to gas ratio. Not all outboards are 50:1. Do a google search and try to estimate the age of your engine by pictures you see on the internet. Then find out what type of ratio you need. Many older outboards ran on 30:1.


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## Siamese (May 9, 2007)

I think white smoke means:
a. You've just elected a new pope
or
b. you have some water getting into the cumbustion chamber

If you have a good outboard mechanic, that's where it needs to go. Might just be a bad head gasket allowing water to go from the cooling system into the combustion chamber. 

I wouldn't give up on the engine, either. They're built like tanks. 

ALWAYS use the freshest gas in a 2 stroke
ALWAYS stabilize your fuel when storing
ALWAYS burn stabilized fuel for a few minutes before storing so the carb has stabilized fuel in it.
ALWAYS use the best 2 stroke oil...Evinrude, Johnson, or Quicksilver.

There are other good oils, but dabbling in other brands will lead you to a bad brand sooner or later. 2 strokes are a lot like diesels...it's ALL about the fuel.


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## jgeissinger (Feb 25, 2002)

*Evinrude 15*

Birdface

Your correct mixture for that year is 50:1, and you can run them even leaner with no real problems. But stick with 50:1. A light bulb came on above my head just now, and I have another question. What kind of oil are you using? You have to use TCW III 2 stroke, in either natural or synthetic oil. If you use regular motor oil it will smoke like crazy and the smoke will be white.


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## Rockter (Sep 11, 2006)

You are mad to think of running the motor leaner than the recommended oil:fuel ratio. The older motors are simply not designed to get by on leaner than that and the older bearings need quite a lot of oil to float them. Quantity matter too.
Stick to the ratios.
The same is true of motorcycles.
A ratio of 100:1 would be suicide on my olde MZ 301 communiust motorpickle. The motor would not forgive it. It needs twice that, 50:1. The manufacturer made that call, and they should know.


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## Birdface (Jul 24, 2006)

Wow, thanks everyone. Much appreciated.

SO... 

1. This was a gas fill at my yacht club dock, first time this year... suspect.

2. I used some West Marine TC-W 3 and some Mercury Marine TC-W3 I believe

3. Motor has been smoking for most of the season more than last season or normally. I have a second 6 gallon tank with different gas and oil, I will try it next weekend. (work trip to Vegas to lose my money, shirts, and pants)

4. Water spray in exhaust? Anything on that?

The pee hole is not the exhaust I'm speaking of, the exhaust is the mid-outport of air exhaust. There's a fine mist of water (I think) being sprayed out of it.

----------------------------
Main Concerns-
1. I need to take my father and aunt out on a cruise next weekend. Last time the motor was run I saw some significant smoke for the full 15 minutes of run.

2. I need to get the boat up a river for storage for the year on Oct 4th. If there's poor wind and my motor's dead.... it's a tow situation.

I need a total of 3 more hours out of the motor before it can be looked at... is this a bad idea?


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## TSOJOURNER (Dec 16, 1999)

i agree with the head gasket idea a few posts back. white smoke and water in the exhaust means you are getting water in the cylinder, and in the 4-stroke world that is a definite blown head gasket. now, being a 2 stroke, there may be other causes, but they will be along the same lines. i don't really know where the water jackets are, but one of them is spraying water into your cylinder, causing very significant pre-mature wear in the cylinder. stop running it now if you plan to get it fixed. it will be a pretty difficult job if you've never been in an engine before.


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## cardiacpaul (Jun 20, 2006)

I second (or third) the head, or head gasket solution. White smoke is water, blue or blue/gray is oil. Do not "lean it out"
heres a test.
Remove both plugs, look at 'em, one will have a dry, ashy, light gray or brown tint but is otherwise clean. The other will be black, oily, wet, or mottled in appearence. Thats the bad cyl. 

It could be the head itself got warped, or just a head gasket. Lesser chances for crank main seal, or split cyl wall / water jacket.


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## tommays (Sep 9, 2008)

I would take a look at the spark plugs as any water or other abnormal things will be easy to see on the sparkplugs


Water will wash sparkplugs clean as new and if you have a something else going on they will be real dirty from poor combustion 


As a matter of fact how old are the plugs


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## TSOJOURNER (Dec 16, 1999)

*do you know what is wrong with this 15*

I have a 15 hp evinrude 2 stroke and it has no power now we have checked the timing the carb the drive the head the compression and we still don,t know why it is so gutless. now does any body now if they are quick or are they not supposed to go fast but or old 9.9 would eat it on the same boat if any body has any ideas that would be great.


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## Vitesse473 (Mar 16, 2008)

Step 1: Dump all your fuel (legally) and start with fresh gas and use the Evinrude/OMC oil. Stick with 50:1. That's the cheapest troubleshooting step. 

Step 2: If that doesn't work, pick it up and take it to a shop. They can pull the plugs and do a very quick compression test (hopefully at no charge). That should always be your first course of action before spending any money.

Step 3: remove the head and check the thermostat. My Seloc manual states t-stats will almost always stick in the open position, which will allow more water to go through the idle relief, and thus exit as a very fine mist. Does it happen at full throttle, too?

Step 4: If the engine is running now and you only need a few more runs, you might just opt to pay the Vessel Assist fee ($96/year) and go sailing (with a VHF radio and cell phone. 

I just bought a 1992 Evinrude 15 hp (E15RENM) for $575, so just make sure you don't dump a bunch of money into it.


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## Rockter (Sep 11, 2006)

A decent compression tester is £20 here. It is easy to use. My olde GT500A motorcycle reads about 150 psi, with the motor run for 10 seconds before I use it. Each piston is 250 cc, and there are two of them. It's a 40 hp motor.


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## TSOJOURNER (Dec 16, 1999)

*steamer outboard*

This engine is and always was a workhorse. If the engine has not been overhauled in the last 6 years, I would fist say that the engine head gasket is leaking. You will not see this much with a compression test. It costs a few dollars for the head gasket approx $25.00

maybe an hour labor. 50:1 is the correct oil mix but remember that when this engine was built ,my guess approx mid 80's TCWII was the oil. This oil has less wax in the mix than the new TCWIII


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## cruisingdream (Feb 7, 2007)

You stated the engine runs fine just smoke (probably steam) from exhaust 
If th pee hole water seems warmer than it used to be this could indicate the thermostat is stuck shut, most ouboard have a pressur bypass so you will have cooling water flow.

1st pull the spark plugs & check them & inside the cylinders if they look normal (a little carbon & brown-black) and not metal clean your head gaskets are probably ok

2nd locate the thermostat housing remove & inspect for blockages and that the bypass is ok & replace thermostat 

3rd The exhaust tube in the lower housing has a gasket that may be burnt through or just deteroriated with age ( also replace water pump while you are down there)

Good luck 
Keith


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## Birdface (Jul 24, 2006)

Thanks CD.

I'm going to pull the motor, buy a stand and do some work on it. 

If I fail.... I buy a four stroke and this is a project engine.... if it's still running at the end of the winter then I'll know my way around it and feel better.


Thanks to everyone.

-Bird


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## TSOJOURNER (Dec 16, 1999)

Bird, sounds like a good project to tackle. i am a traveling marine mechanic, happy to assist , please feel free to call with any questions you may have.

Good Luck
Bill


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## philsboat (Oct 16, 2006)

If you do repair the 15 Evinrude be sure to change the fuel pump diaphragm.They stiffen up and crack with age and will allow gas to bypass the carburetor and go directly to the base which will give you an excesively rich mixture,causing it to stall and run rough.This can be proved by squeezing the gas tank bulb while it is idling.If the motor dies or falters it is probably the fuel pump diaphragm.
Saw this on a friends 15 Evinrude this summer and it happened to me years ago with an 8 Marriner(Yamaha).

Phil


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## Birdface (Jul 24, 2006)

In true noob fashion I'll renew this thread to say that I've broken down and bought a new O/B.

I went over a Tohatsu v.s. Mercury comparison and in the end paid $300 bucks more for a 9.9 hp Mercury 25'' because of the in-tiller shifter and the "bigfoot" gear box and prop. 

The 25 year old evinrude will end up in my basement for me to work on and eventually may become a dink O/B.

Thanks to everyone for the assistance in this thread.


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## sailingdog (Mar 19, 2006)

The bigfoot gearbox and prop was probably a good idea, since this is for a sailboat. I hope you got a long-shaft model.


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## Birdface (Jul 24, 2006)

Xtra long. 25 inches of glory.

I hope to never hear my prop leave the big blue, but I'm sure that's wishful thinking.


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