77 Johnson 9.9 HP Outboard

Discussion in 'Bubba's Outboards' started by catfishcentral, Nov 26, 2008.

  1. catfishcentral

    catfishcentral New Member

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    Hey Bubba or anyone else for that matter.

    I bought a nice older 77 Johnson 9.9 about a year ago. I ran it for the first time a few weeks ago...ran it about a mile on on river, it ran perfect with no problems. I took it out today and after about a mile it started to run bad. I was able to make it the mile back but either ran it at a very slow foward speed or gun it and it would surge then slow down back and forth. Now the motor wouldn't die if I kept it running slow or gave it as much gas as I could. It would die immedately if you tried to speed it up or slow it down. Now the motor sat for a few years before I bought it and ran fine for the first couple of miles but didn't know if running it for the first time in awhile would break lose some old crap in the engine. I brought it home pour seafoam in the tank and also seafoam deep creep in the carb and ran it with the muffs on. It seemed a little better but should I just keep trying to run whatever it is out of the carbs or do they just need to be rebuilt?


    Also I notice there was gray oil inside the prop. Also black oil running on the steering shaft? I drained the lower unit oil and it didn't look like there had been any water in the lower unit oil. Is there a seal behind the prop shaft where oil could be leaking out? I didn't think there was any oil for the outboard besides the lower unit so didn't know where this black oil would come from. I also didn't know if the 2 cycle oil from the exhaust put that on the prop. I've never seen anything like that on my big yamaha.

    Thanks for any advice or help.

    Chris
     

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  2. BKS72

    BKS72 New Member

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    3,361
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    East of KC
    First pic looks like grease running out of the lube points on the steer shaft. Second is most likely residue from unburned fuel that's collected in the prop from the exhaust. Neither one of them would worry me. The large amount of unburned fuel at the exhaust could very well be a symptom of the fuel problems you're having.

    Only my personal opinion, but for no more work than it is I'd tear down the carb, soak it and clean it till it looks new, and rebuild it. It'll save you a lot of aggravation. If you haven't already, might as well throw a new plug in it and change all your fuel hoses at the motor. If they've sat that long they've probably dry rotted to the point that you might be losing suction.

    Doesn't sound like anything that about $20 and an hour and a half won't fix.:big_smile: Good luck!

    Branden
     

  3. catman george

    catman george New Member

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    440
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    Oklahoma
    Chris- I agree with BKS72. I think Seafoam in the fuel and a rebuilt carb should fix the problem. You don't have time to fiddle with a headache with your work related travels eating your spare time. Rebuild over the winter during the Xmas season when things are slow.

    The 92 model 18 HP Nissan that I recently purchased turned my 14' lonestar into a guided missle. 2 people on board and it still fish tails a little when running wide open.

    catman george
     
  4. catfishcentral

    catfishcentral New Member

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    Thanks Brandon :big_smile:

    I wondered if that oil inside the prop was just be unburned oil from the exhaust but really wasn't quite sure...never had a little motor like this before.
    I'll have to look for lube points on the steer shaft seemed like a lot of oil.

    I put in new plugs, water pump and changed the lower unit oil before taking it out. The fuel line and bulb from the tank to the motor is new. I'll double check that fuel line to the carbs and probably rebuild the carb sometime this month. Never rebuilt a carb before but it can't be too hard to do. I heard those 9.9 Johnson and the 15 horse johnson from this time period were the exact motor except for the carbs. Heard they can be changed out to make it a 15 horse...not sure how much work or headache it might be though.
     
  5. catman george

    catman george New Member

    Messages:
    440
    State:
    Oklahoma
    Chris- My understanding is that you just need to change the carb jets to change the engine to a 15. Hopefully some one else that has a better knowledge than myself will confirm or correct me.

    George
     
  6. catfishcentral

    catfishcentral New Member

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    That seafoam is pretty good stuff there. Between a can in the tank and deep creep in the carbs it ran much better today. The only problem now is the rubber in the prop went bad. I hit a log on the way back and I think that's what finally loosened that rubber hub. The boat wouldn't go at all at higher speeds, just had to crawl back to the ramp. They are a easy fix at the prop shop, have had my other prop's do that over time.
     
  7. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    I'm not sure on what else other than the carbs or jets you might need to change to bump it to 15 - might have to adjust timing as well, but I don't know.

    Chris, the oil in the first pic could be fuel running from the carbs as well if the motor is stored in the up position. Hard to tell with out being there, (I've never had one of these motors) but there should be a grease zerk on the mid somewhere on the steering shaft to lube it. The seals or bushings might be wearing and allowing the grease to work it's way out.

    Carb rebuild should be fairly simple, just watch your linkage when you take it apart (or take a pic) since it can be a hassle. If that's like my uncle's you might have to take the starter recoil off of it. We pulled the carb off it last year and I remember we had to remove a couple of pieces to get to the carburetor mounting bolts. Good luck!

    Branden
     
  8. LureheadEd

    LureheadEd New Member

    Messages:
    197
    State:
    Geogia
    Hey Chris, after 20 years of wanting to ramp up my 78 9.9, I finally put a 15hp carb on it this past year...Did'nt do much good...From one of the outboard message boards I remember that some pro mechanic said you had to change the reeds under the power head also...The mech that does my impeller (I'm too chicken , it's a mental thing) also told me I was wasting my time and money...But others that have done it swear it works...

    Your power problem should be just a fuel system problem (old?/bad float?comes to mind), but it also could be an ignition problem...I changed out the power packs on mine a few years back when I had the same sort of trouble (after doing the fuel system ) and it made all the difference in the world...Also check your compression just to make sure it's up to par...

    All this mess to figure, what a pain for us non-mechanically inclined folks, but if you have one of these motors that is "right", you'll love it... A little bit of care and it'll last a lifetime...