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Fuel out the exhaust

Discussion in 'Boats and Motors' started by bkr43050, Aug 20, 2004.

  1. We have an old Johnson 10HP motor that we use up in our cabin in Ontario. I brought it back this last season and had it fully serviced (replaced head gasket, water pump impeller, carb clean, fuel line filter placed, replace lower unit lube). The motor ran great after this and it really ran pretty well before that but I wanted to be sure it stayed that way. A couple of things that I noticed though while running the boat this past week was that when I would start it much of the time I would get some white balls of something coming from the exhaust. It appeared to have gasoline in its composition because of the way it dispersed quickly. I also noticed that it seemed to be exhausting a bit of unspent fuel when idling the motor all the way down. I found no indication of leaks in the fuel lines so I am pretty sure that it was coming from the exhaust. The motor has the adjustments on the front for lean/rich for both low and high speed adjustment. Does this sound like an issue with these adjustments? I mix the fuel at a 50:1 which is what I use on my motor here as well. As I mentioned the motor ran great other than this. Does anybody have a good guess on what this may be?
  2. Hetfieldinn

    Hetfieldinn Staff Member

    It's just what you thought it was/is. Spent exhaust. It's normal. If you do a lot of low speed motoring/trolling during the day, you might want to end the fishing session with a high speed/rpm run to blow out any build up.

  3. sauguy

    sauguy river & muskie angler, dayhiker

    i have the same thing on my 1982 johnson 9.9. i took it to haines marine in andover and they told me the same thing. it is normal on the older motors if you troll alot. at the end of each fishing day i open it up wide open for a while. that gets rid of most of it.
  4. Just just install a spark plug into your exhaust. It will burn out all of the gas.

    Yea i was joking, i dont really think you should do that. It does work though, my buddy did it to his truck. He has 2 foot flames shooting out his exhaust at the push of a button. Pretty cool, haha
  5. Thanks guys for the explanation. I was pretty sure that was it but thought I better confirm it with someone who has more experience on outboards than myself.

    KSUFLASH respect our rivers please

    1969 60HP Evinrude Motor. Does the same thing. It is pretty normal with older motors.