1986 9.9 Johnson gas/oil leaking from prop exhaust

[Blake0912]

My 9.9 Johnson is leaking a heck of a lot of burnt oil/gas from the prop , the inside of the prop is covered with it after I run it on my muffs. I don't use this motor much in the water since its my kicker and I don't want to run it all the time in saltwater for no reason.

I checked the gear oil twice and it had no indication of water intrusion and the stuff coming out of the prop Deffineatly smells like gas but it's dark brown With a hint of blue ( oil color ).

My first thought was I had taken it to a machanic to fix the rope start and he ran it in a very dirty test tank so I thought it had sucked up a lot of dirty / oily water but I've ran It for about 30 mins pushing the boat around , and also on the muffs I start it up every weekend before I head out.

The motor runs fine and starts on the first pull , I can even start if by spinning the fly wheel by hand. Is this normal for these motors to leak that much oil/gas out of the prop or is this a sign of some gasket going bad ?

 

[raczekp1]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

1.
termostat juststack in open position
2.
leaking fuel pump membrane
3.
carb set too much reach

 

[Blake0912]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

Fuel pump is new and its not leaking fuel. Carb should be set correct , machanic adjusted it while he was fixing the rope start.
But im not sure about the thermostat I've never replaced it. How would a stuck open thermostat cause a motor leak out fuel?

Thanks your your reply

 

[Blake0912]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

Ah if the thermostat is stuck open the motor won't get hot enough to burn the extra oil so I will just leak out if the exhaust ( Just guessing )

Will this hurt my engine because it's not getting warm enough ?

 

[OptsyEagle]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

Ah if the thermostat is stuck open the motor won't get hot enough to burn the extra oil so I will just leak out if the exhaust ( Just guessing )

Will this hurt my engine because it's not getting warm enough ?

Yes. But you should note that your condition is quite normal for motors that are run on muffs. I keep a pan under all my motors, all the time, for this very reason. I don't always get the goo but it's nice to have a pan under it in case I do. When running in the water, I usually try to open it up (WOT) for a minute or so before I bring the boat into the dock, just to burn that off, if I can.

 

[Blake0912]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

thanks for your input. I guess I dont really have an issue then I was just making sure.

 

[kenmyfam]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

Unburnt 2 stroke oil likely. Nothing to worry about.

 

[the machinist]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

As kenmy & opty say, this is normal if you use the motor a lot in slow speed running like trolling & do not run it fast for long enough to allow the motor to really reach a temperature governed by the thermostat. You will get a lot of brown/milky or even black oily gunk dripping out of the prop for a week or so after useage. You also may get your spark plugs fouled oftener.

 

[Blake0912]

Re: 1986 9.9 Johnson gas/oil leaking from prop exhaust

Thank you for the replys, Yes its mainly used at a "trolling" speed since its a kicker. If the winds are calm this weekend Ill put it on my flat bottom and give it a good WOT run. I figured that was the case because my 40 merc will do the same thing if I run it on my muffs for a while.