'70s era Johnson 10 horse: massive smoke

[closerhauled]

I can either sell my outboard to the military as new stealth technology for boats due to the huge fog of exhaust it emits, or I can fix it. What could cause this otherwise nice idling engine to belch so much exhaust from the little hole right below the powerhead? Shouldn't a lot of it come out down by the prop? How can the total amount of exhaust be reduced? (other than my not starting it)

 

[petryshyn]

Re: '70s era Johnson 10 horse: massive smoke

morning closerhauled:<br /><br />As far as exhaust goes, what comes in, must go out!<br />-what ratio mixture are you using?<br />-what type of oil?<br />-is it fresh fuel?<br />-is it smoke.....or steam?<br />-does it smoke all the time?<br />-how does it perform?<br />-how does it idle?<br />-has idle mixture been adjusted?<br /><br />this should point us in the right direction...

 

[12Footer]

Re: '70s era Johnson 10 horse: massive smoke

Use a better oil. This is the best way to cut-down on smoke. Using fresh fuel is another. Don't let the fuel sit in the tank for months. It will get stale,and the concentration of oil-to-gas will go up,as gas evaporates,oil wont.<br />If it runs good, there is probably nothing wrong with the engine, but you might want to run a compression test.<br />For oil, I reccommend Wal Mart's Supertech TC-W3, Or Quicksilver Super Premium. My Force engine will smoke heavily on anything else I try. One more tip, make sure it is 3oz of oil to 1gallon gas, or 50:1 ratio.<br />I hope this helps.

 

[closerhauled]

Re: '70s era Johnson 10 horse: massive smoke

Thanks for the tips, 12footer. Good questions schematic: in order:<br /><br />1) 50:1<br />2) Lubrimatic<br />3) three months old gas<br />4) acrid smoke, no steam<br />5) don't know if it smokes all the time yet, only had it out once; just bought it. Seemed to be less at low rpm<br />6) Ran OK at idle (other than smoke) then ran good for about two minutes at high rpm then quit. Opened cowling and saw no gas in filter chamber. Pumped gas in and it ran again.<br />7) idles OK<br />8) I fiddled with the idle misture knob on the front with no apparent affect. Have no real clue how to tweak those knobs...

 

[petryshyn]

Re: '70s era Johnson 10 horse: massive smoke

If it were me:<br /><br />>mix fresh fuel, tcw3 rated oil, careful on the ratio procedure!<br /><br />>restart engine, warm up a few minutes, while idling...adjust slow speed adjusting screw(top one). turn in until engine starts to miss, then back out till just smoothens out. Its a little lean at this point, but it'll answer some questions if the smoke dissipates. <br /><br />>you're also describing a possible fuel system problem as well. does the ball get hard and stay hard when you squeeze for 10 seconds? or does it slowly bleed down?(possible cracked diaphram in pump could cause 'out of fuel' and a rich mixture after primed which would account for both problems)

 

[closerhauled]

Re: '70s era Johnson 10 horse: massive smoke

thanks for reply, schematic. By "top one" do you mean the outer ring or inner ring? There is a smaller red one insent in a larger outer ring. The outer ring is marked rich /lean. The innerone is not marked.<br /><br />I'll try the mixture recommendations.<br /><br />Re: the ball getting hard and staying hard, aside from the great straight line (I'll resist)... It seems to get hard and stay hard just fine til it runs itself dry. Then I have to pump some more to restart.<br /><br />I wish I had more experience with OMC products.<br /><br />Thanks for your help...

 

[mit3k]

Re: '70s era Johnson 10 horse: massive smoke

Your engine sounds alike like mine it's a vxl-13a 1967 70 hp johnson<br />and mine also smokes runs fine though