1986 Johnson 6hp, exhaust leak through steering shaft?

[redfishsc]

This is a Johnson 6hp, 1986.

There is an exhaust leak of some sort. It seems to be coming from the areas indicated with the yellow arrows in the pic. It really seems as if it's passing through the steering shaft, almost as if it's getting into the steering shaft from the top down. Either way, smoke and fumes will come out of the places indicated with the arrows. The engine will stifle and run terrible if I leave the cowl on, but if I remove it, it runs decent. Sometimes it hesitates a bit when accelerating but never stalls, and can idle or troll at idle speed pretty decently with the cowl off.




I do not know if this matters, but the gear shift knob does not shift into reverse. Seems like it is in the same place as the exhaust leak, and I was told that someone bumped it a while back (previous owner). Not sure what happened other than the shift knob got jammed in a little, if you try to put it in reverse, it hits the lower cowl and you can tell something inside is jammed up. I wasn't going to fiddle with the reverse for now but if I have to remove any of this, or if it's related, I'll try to fix it.

Any suggestions on how to find out the problem, other than just rip it apart? I'm a rookie at working on these things.

 

[nwcove]

Re: 1986 Johnson 6hp, exhaust leak through steering shaft?

get a base gasket, remove the powerhead and replace that gasket. while its apart you can assess the shifter issue. not sure how you would see a leak where the bottom arrow is tho, unless you are running it out of the water....which is a big no no!!

 

[redfishsc]

Re: 1986 Johnson 6hp, exhaust leak through steering shaft?

No, I'm not running it out of the water, I run it in a barrel when working on it. When I'm out in the boat, I have to use a jack plate to get the AC plate up even with my keel. This motor is a long shaft and my boat's transom sits fairly low.


When using the jack plate, sitting still in the water, the water level is exactly where the arrow is (there at the top of the shaft extension). Water intake is well below the water level. The exhaust I can hear babbling on the water surface as it spits out of the spot indicated. It really seems to be coming out of the steering shaft.


Do you know of any basic instructions on removing the powerhead? I've never taken one apart like that. I am a bit of a rookie with outboard motors. I'm not afraid to try to work on this motor since it's so old (and was basically free), I plan on eventually getting a 9.9 or 15.... maybe.