Smoky Outboard

[chriskeeler1982]

Hi, sorry if this has been covered but I need some friendly advice. I have just bought a second hand Mariner 15hp 2 stroke engine about 20 years old. I’ve taken the engine home, filled my wheelie bin and mounted the engine. Filled the external tank with 10 litres unleaded from the petrol station and mixed in 200ml of 2 Stoke outboard oil.

When I came to start the engine it took a good 20 pulls to start but then turned over. It ran well and has continued to do so, now when I stop it, it starts on the first pull. The engine seems to tick over well and goes into forward and reverse. My issue is with lots of white smoke from the engine….comes from around the back of the engine. I don’t know what’s wrong and just checking I’ve done nothing wrong. I went back to the seller to question him and he said I’ve run it dry and broke the engine! I have also noted it leaves the water in the bin very oily and now I have stored the engine inside it smells heavily.

Have I done anything wrong? Can anyone advise what the issue maybe? How much water does the engine need to be sat in…have I run it dry?!

Many thanks.

 

[Minerva]

I think what you are describing is a “feature” of two strokes and the reason why the sale of new ones were banned…

 

[Graham376]

White smoke can be overheating. You don't mention if it has a tell tale and whether it's passing water.

 

[Chiara’s slave]

White smoke on a 2 stroke motorcycle is the clutch side crankshaft oil seal. I have no experience of it on an outboard, but on a bike, that pulls gearbox oil in to the crank case. Not sure how that would happen on an outboard, the leg isn’t full of oil. It might be water though, the white smoke could be vapour. Any loss of performance.? They usually idle ok, cos there’s not much negative crankcase pressure at idle.

 

[chriskeeler1982]

Been used to 2 strokes in the past which smoke, but this is excessive in my mind. The tell tale is passing water, I moved the engine to a different stand because it was warping my bin and then put it in less water and at that point the telltale was not flowing all the time. But the water was still well up over the prop and half way up the shaft. Haven’t tried it on the water so can’t comment on performance….wanted to check it works after I bought it and not gone further than running it in a bin and being smoked out!

 

[CliveF]

200 ml in 10 lt is a 50:1 ratio. Which is good and safe from a lubrication point of view but will tend to produce more smoke.

at 20 years old it is possibly meant to be 100:1 which would give less smoke and as long as you are not thrashing it every where will be adequate lubrication.

Make sure you check the correct engine manual for the mix ratio BEFORE you change though.

Regards Clive

 

[chriskeeler1982]

Clive, that’s interesting, thank you. It does seem to run well apart from the smoke so that is definitely worth looking into. Is it relatively standard for the water it sits in to become quite oily on the surface?

 

[CliveF]

yes it is totally standard. the oil in the fuel does not burn it lubricates and comes out with the exhaust gases , which come up through the water that collects the oil.
In a drum it is all in that small surface area rather than being spread over masses of water as you speed away from your pollution

 

[andsarkit]

I have a Yamaha 15 2T which is possibly quite similar. ( there was a lot of badge engineering on outboards). The pee hole should produce a strong jet of water and I found it blocked quite easily. You might be able to remove the cover and see a pipe feeding the pee hole which you can pull off to see if it improves the flow. You can feel the side of the engine to see if it is overheating. It should be obvious if the smoke is steam as you will not get a water flow at that point. I always carry a piece of wire to clear the pee hole if it becomes blocked which I think comes from internal corrosion of the aluminium parts.
I doubt that you have damaged the engine as the smell of an overheated engine is quite noticeable and you have only run it for a short time under no load.
It is quite normal for the water in the tank to get quite oily as said above, this was why they were discontinued. My engine from about 1985 has 100:1 written on the side but I have always run it on TCW3 oil at 50;1 as I think this improves engine life.

 

[geem]

I have a Yamaha 15 2T which is possibly quite similar. ( there was a lot of badge engineering on outboards). The pee hole should produce a strong jet of water and I found it blocked quite easily. You might be able to remove the cover and see a pipe feeding the pee hole which you can pull off to see if it improves the flow. You can feel the side of the engine to see if it is overheating. It should be obvious if the smoke is steam as you will not get a water flow at that point. I always carry a piece of wire to clear the pee hole if it becomes blocked which I think comes from internal corrosion of the aluminium parts.
I doubt that you have damaged the engine as the smell of an overheated engine is quite noticeable and you have only run it for a short time under no load.
It is quite normal for the water in the tank to get quite oily as said above, this was why they were discontinued. My engine from about 1985 has 100:1 written on the side but I have always run it on TCW3 oil at 50;1 as I think this improves engine life.

It's quite well documented that longer service life comes from 50:1 on Yam 2 stroke outboard. Some of the older models say 100:1 but this is from an era when emissions was a concern over engine life. Run 50:1 and accept the smoke. In reality, when they warm up properly, the smoke is negligable. It's only the initial start that is smokey until the engine is hot

 

[chriskeeler1982]

I’ve tried, but can’t seem to upload a video….its a lot of smoke! It does concern me. Will keep trying to upload.

 

[chriskeeler1982]

 

[chriskeeler1982]

This was a photo when I revved the engine up in neutral

 

[geem]

This was a photo when I revved the engine up in neutral

Normal when cold, on 50:1

 

[chriskeeler1982]

Well that’s surprising but good to know. How long would it usually take to warm up and smoke less?

 

[geem]

Well that’s surprising but good to know. How long would it usually take to warm up and smoke less?

If you put it under load after a minute, mine makes no more smoke. It's very smokey when first started. My 15hp is used daily. It's a 2016 15hp model that had a hard life but runs well

 

[chriskeeler1982]

Geem thanks for the messages….gives me a bit more confidence the engine is ok.

Can you or someone else confirm that as long as the engine is submerged a decent amount above the anti ventilation plate that is sufficient to run it and flush it through??

I have attached a photo and wanted to know if submerging it up to my finger is ok? Thanks

 

[ylop]

Yes that’s plenty deep enough - but if you put it in gear in the bin be very careful a lot of the water will leave the bin! Even at tickover it should start to clear after <5 minutes.

 

[Dellquay13]

Geem thanks for the messages….gives me a bit more confidence the engine is ok.

Can you or someone else confirm that as long as the engine is submerged a decent amount above the anti ventilation plate that is sufficient to run it and flush it through??

I have attached a photo and wanted to know if submerging it up to my finger is ok? ThanksView attachment 199111

I have marked where the top of the water pump will be, if you could get a bit more water in the tub it would be better than your finger position if the water is agitated a lot.
The smoke in your other photo will be more concentrated in the bin than when the motor is in open space on the back of a moving boat.

 

[VicS]

Geem thanks for the messages….gives me a bit more confidence the engine is ok.

Can you or someone else confirm that as long as the engine is submerged a decent amount above the anti ventilation plate that is sufficient to run it and flush it through??

I have attached a photo and wanted to know if submerging it up to my finger is ok? Thanks

When running in a bin or tank the water level should be several inches, some would say 6 inches , above the level of the water pump,

If you do not know that the water pump impeller has been changed recently it would be prudent to change it before you start using the engine.

Once you get it on the back of a boat and take it for a good run the smoke will soon clear.