I know is a 2 stroke and it should smoke...

[fch2cxr]

200 HP 1991 Johnson, I trying to figure out why it smokes so much at idle, no VRO, mix 50:1, I understand it supposed to smoke, but this one leaves a smoke screen as it idles and I think it spits fuel/oil thru the exhaust as I can see rainbows in the water cause by of unburned fuel/oil...I rebuilt the carburetors last week encountering no improvements what so ever? any pointers??? Other than that it starts right away W/O issues?

 

[jdsgrog]

Re: I know is a 2 stroke and it should smoke...

sounds like it's burning rich. did you check the plugs? they could tell you a lot, especially if they are fouling. Also, how is the boat at higher rpm? does the motor have a low speed adjustment/needle valve(s) on the carbs?

 

[ezeke]

Re: I know is a 2 stroke and it should smoke...

It should respond well to a thorough decarb followed by servicing the recirculation check valves. You should have a Schrader valve on your primer solenoid that makes the de-carbon process simple if you use an aerosol treatment such as Engine Tuner. http://shop.evinrude.com/dyn_prod.php?p=763644&k=116692

You may also find the situation will improve if you use blended or full synthetic TC-W3 oil.

One other thing is that the engine drains properly of excess oil and gas mixture in the running position, but not if stored tilted up.

 

[Chris1956]

Re: I know is a 2 stroke and it should smoke...

Check the pulse lines on the fuel pump for liquid fuel. If you find it the fuel pump diaghram may be leaking raw fuel into the crankcase. Look for flooding carbs as well.

 

[ezeke]

Re: I know is a 2 stroke and it should smoke...

If the pulse line is contaminated, you should see a noticeable difference in the cylinder #6 spark plug when compared to the others.

 

[fch2cxr]

I know is a 2 stroke and it should smoke...

I'll check all that guys, but my pump is about 3 months old, I just re did the carbs, all plugs look the same black and wet all the time, when motor drains excess up right where does the fuel goes???, plugs are not fouling, have had the same plugs for the season, might have 10 to 15 hours on them, no low speed adjustment/needle valve(s) on the carbs, only orifices...
I think my next step will be thorough de-carb followed by servicing the recirculation check valves, is that a hard task???

 

[ezeke]

Re: I know is a 2 stroke and it should smoke...

Two stokes are self-draining and drain best in the running position; most of the unburned fuel and gas goes out with the exhaust and water at the propeller. There is some residue that goes back through the recirculation check valves and some drains back to the air silencer from the crankcase.

If the engine is running at the correct temperature, the build-up should be minimal with a carbon treatment in the fuel. Major outboard manufacturers all have carbon treatment additives, and some oils have carbon treatment built in.

 

[LubeDude]

Re: I know is a 2 stroke and it should smoke...

I have a 1996 Johnson 200, and it smokes more than I think that it should at Idle and I am running 100 Synthetic. Smokes a lot when I start it every time! I have to assume that it's normal for the beast!!

 

[ezeke]

Re: I know is a 2 stroke and it should smoke...

If you think it smokes now, try trolling for 4 to 5 hours on regular non-synthetic. My 225 is a 1990.

The main thing to remember is that it is not just oil, but a combination of many different factors that determines the amount of smoke that the excess oil will produce. Probably more significant than the general quality of the TC-W3 oil is that the thermostats are working correctly and that the motor is not over-propped.

 

[iwombat]

Re: I know is a 2 stroke and it should smoke...

ezeke brings up a good point about proper operating temp. thermostats often fail in the open position. Be sure your motor is getting up to proper operating temps.

 

[kenmyfam]

Re: I know is a 2 stroke and it should smoke...

My 140hp Looper smokes a lot at initial start up from cold. Always has. As soon as it warms up it is fine, even after trolling for a while it will give a quick puff of smoke and that's it.

 

[ezeke]

Re: I know is a 2 stroke and it should smoke...

200 HP 1991 Johnson, I trying to figure out why it smokes so much at idle, no VRO, mix 50:1, I understand it supposed to smoke, but this one leaves a smoke screen as it idles and I think it spits fuel/oil thru the exhaust as I can see rainbows in the water cause by of unburned fuel/oil...I rebuilt the carburetors last week encountering no improvements what so ever? any pointers??? Other than that it starts right away W/O issues?

I think that the discussion has gotten off the point that fch2cxr never mentioned start up smoke which I'm sure that we all agree is normal on older two strokes. The question dealt with smoking at idle which sounds as though it is constant during normal operation on his motor. I have the 1990 version of the same motor, which I use for fishing, mostly trolling, and which does not smoke once warmed up. I use premix on that motor.

 

[Cricket Too]

Re: I know is a 2 stroke and it should smoke...

Yeah I have twin 2000 200hp Johnson's on one of my boats and at cold start up they create a smoke screen that you can see from down the road.

It gets better once they warm up, but they always smoke a decent amount, if I sit at idle, even when they are warm, they smoke pretty good, I sometimes use it to get rid of bugs back at the dock when I'm cleaning up.

fch2cxr....does it get any better when it warms up, or is it always the same as a cold start?

Is the mixture any richer on cold start up? I know Quickstart advances my timing, but does the mixture get any richer when cold?

 

[fch2cxr]

I know is a 2 stroke and it should smoke...

No, mine smokes the same warm or cold... I'm going to take a look at the thermostats, as my motor never gets hot while going thru no-wake zones (basically idle in gear, in gear at ~850 RPMs) the motor is always warm to the touch but never hot at this RPMs range, that could be causing the smoke, it does not smokes at high RPMs (at least not noticeable)