1989 Johnson 20HP HELP

[northwoodslivin]

hey guys,

figured I would make a new thread as my old one was way to large to follow things.

Ok I have a problem. I have this sneeze on idle, I cleaned the carb and all seemed well, got out on the lake after letting it sit a few weeks and it is doing the same thing, took the carb off and cleaned it last night, also installed this fuel filter that is to be used with carbed outboards. When I start the motor it will run "still sneezes" and now I am thinking my fuel pump is shot, the fuel filter will empty out, and I have to press the bulb to fill it back up or else the motor will run it's self out of gas. My father seems to think the fuel filter is to small, I dont think so as this filter can also be used for automotive use on carbed motors as well, so I think the flow of the filter should be more then enough. I took the fuel filter apart and inspected for any dirt, nothing. However I am noticing little tiny black particles in the filter it's self.. I am stumped and ready to sell the darn thing.

When I had it out on the lake last it will run fine at WOT, but often kick and cough leaving a big plume of smoke rising out of the water when it does so. I suspect my low speed jet is again plugged, must have been some junk in the fuel line to the carb, or maybe my fuel lines are getting old, but they look good on the outside.

Thoughts?

 

[Vic.S]

Re: 1989 Johnson 20HP HELP

If pumping the bulb keeps it going properly it is a fuel supply problem not a dirty carb.

It could be a defective fuel pump or it could be an air leak into the fuel line. Fuel connector being prime suspect for that.

Less likely a restriction in the fuel system.

Ethanol in the fuel may be attacking the fuel lines. The black bits suggest this if the fuel in the tank is clean. If they are not alcohol resitsant then you will nned to replace them with alcohol resistant ones

 

[northwoodslivin]

Re: 1989 Johnson 20HP HELP

Vic,

So I went back outside and took out the silicone I had put inside the idle jet fitting which was there from before "I am taking it this is to prevent the jet from dialing out from vibration. Started up the motor and it was doing the same song and dance. So I stuck the screw driver on the jet screw and started adjusting it, well... the sneeze is gone now and it runs like it should again, also put some seafoam in the gas. Whew!

Question. The fuel filter, I was under the impression that it should be full of close to it, it is actually empty when running, you can see the gas trickling in, however I am not sure if this is right, when I shut the motor off you can see it bubbling in the area where the filter screen is, is this normal?

Second question and a very important one I would like to know. When I bought the gas tank new and the fittings, I just tightened them onto the tank with nothing, should I perhaps put some silicone on the threads to prevent any air leaks? I did put hose clamps on all the fittings, when I connect the quick connect end of the line to the fuel tank fitting, it does not click, actually there is some play between the fitting and connector, wondering if this is normal, and do I need to put anything on the threads that screw into the tank and also on the brass fitting threads that screw onto the tank?

Think I am going to go install my new fish finder now
Very much appreciate your help!
PS
Sorry, I am a newbie to boating, this is my first boat so this is all new to me!:redface:

 

[northwoodslivin]

Re: 1989 Johnson 20HP HELP

Everything seems to be going well now.

Thanks

 

[wilde1j]

Re: 1989 Johnson 20HP HELP

Silicone really doesn't belong anywhere on an outboard that I can think of. The are thread sealers designed for gasoline, such as Gasoila and similar products that are not attacked by oil and gasoline. For tank fittings, plumbers teflon tape is fine to use, as long as you make sure none of it gets into the gas line.

It looks like the low speed mixture has several "O" rings associated with it. Perhaps replacing them will stop the air leaks or perhaps the needle is worn. In any case, these aren't expensive parts.

 

[northwoodslivin]

Re: 1989 Johnson 20HP HELP

The needle is metal, looks great, as does the rubber o ring. I was told that at the top of the brass fitting where the low speed jet screws into to put a blob of silicone to prevent the jet from vibrating out of adjustment.

I put a bead of silicone around the fittings on the tank, all seems well now, wont know till I take it back out on the lake but it is running much much better then earlier today!

Thank you for your input regardless~!