Guidance needed on a '96 60 HP Johnson ...

[B4CN4S]

I am looking for some guidance on operating and maintaining a 1996 60 HP Johnson outboard (Model Number - J60TLEDR), owned by my family since new. Generally, it's in quite good condition, has been well-maintained over the years and has not been the subject of abusive treatment. It's used ~5 months a year in salt water, winterized each year for the winter by the boat yard that hauls it.

First, the operational problem; gradually over the past few years, idling has become progressively more of a problem. More often than not, it will stall when being shifted into reverse to slow down, for example, when approaching a dock, mooring, etc. When I ran the engine for the first time this year (earlier in the week), it started up quickly but ran quite poorly; it was unable to idle, it would run roughly at most speeds and didn't develop full power or run smoothly at full throttle. I suspected that the fuel wasn't the freshest, so I drained the three carburetor bowls, forced clean, fresh fuel through them and am now running the engine on a new, external fuel tank with fresh fuel and some Sea Foam, bypassing the boat's internal fuel tanks (and old fuel) but using the engines external oil tank and injection system. That smoothed things out quite a bit but the engine still isn't running well at high speed and doesn't idle well (at some mid-range throttle settings, it seems to run better). The spark *seems* to look about the same for the three cylinders at idle, but I haven't checked much else.


I'm happy to invest in a good manual as well as a few specialized tools and parts to tune and maintain this engine, so I'd gratefully appreciate any advice in those departments.

Lastly, will the manual help me diagnose what's currently wrong with this engine, and if not, can someone point me to a good diagnostic routine that I can use to narrow down the field of potential problems? For example, "First, start with a compression test, look for numbers like ..., If that's OK, then, test the ignition system by using a gap tester ..., If that's OK, then, check the reed valves by ..., If that's OK, then, ... etc., etc., etc.

I'm quite willing to put in some effort here but I'm hoping to do it in an efficient way; any advice will be appreciated.

Thanks in advance.

[boats.net]

Need to run a compression test, check for spark on all cylinders and probably need to remove and clean carbs.

[B4CN4S]

Thanks for the quick reply; I'll do as you suggest.

Any recommendations on a good shop manual?

Thanks again.

[boats.net]

You can get factory manual at Original outboard product and service manuals for Johnson, Evinrude, Gale, and OMC

[B4CN4S]

I finally had a chance to get to the boat last Thursday; here's a summary of what I found, what I did and where things are now.

Even running on fresh, clean, straight fuel in a new, 6 gallon tank, engine ran exactly as before; quit abruptly after a two or three seconds and would only stay running (until it warmed up a bit) with the manual switch on the fuel primer solenoid thrown; extremely rough at virtually all speeds, wouldn't idle, lots of smoke (especially upon start).

After warming up engine (by going for 15 mount ride with engine running horribly), shut engine down and removed spark plugs (new at fall servicing for winter); all three were completely covered in black grit, and very oily. Cleaned and dried plugs. Also noted that each carb throat inlet was covered in red, oily fluid -- presumably, OMC 2 stroke engine oil.

Compression test:

Cylinder # 1 - 145.5 psi; cylinder # 2 - 145.8 psi; cylinder # 3 - 150.0 psi. (I did not perform a leak-down test.)

Ignition test:

Adjusted spark tester gap to 1/2 inch and all three coils had very similar sparks bridging the gap when engine cranked with starter. Somewhat hard to see the spark well in the bright sun light, even when shaded, but the appearance was the same for all three and one could clearly see the spark.

Carburetor cleaning:

Removed each carb, one at a time; disassembled all removable parts, gaskets, screws, etc., but not throttle plates. Cleaned all surfaces, inspected each jet/orifice and found a few passages with varying amounts of black carbon-like buildup and two air passages (intermediate air bleed orifices) completely blocked, on carbs 2 & 3. Reassembled carbs, set idle mixture screws to 2.75 turns out from seated and reinstalled carbs.

Engine started well (without choke), and would idle without problem, albeit somewhat roughly. Drove boat around for 10 minutes to warm engine and while improved immeasurably, still not running what I would consider well. Adjusted idle mixture screws in 1, 2, 3 sequence, with marked improvement on carbs 1 & 2 and no difference on the bottom carb, what I'm referring to as #3. In fact, the idle mixture screw seemed to have no effect whatsoever on carb #3. I could screw it all the way in and out enough that the spring was no longer effective with no discernible difference. I left it at the 2.75-turns-out-from-seated position and went for another test run.

Engine ran better than it has in years, although it would hesitate for a half second or so when the throttle was opened rapidly. Otherwise, it seemed to run pretty well at intermediate and full throttle (although I'm not sure it's reaching full RPM, which I recall being in excess of 5K; it now gets to 4.7 or 4.8K).

Returned to shore, shut engine off with key, removed spark plugs and noted that #'s 1 & 2 were as clean as when I installed them, although they appeared slightly wet and smelled faintly of fuel (I assume as a result of killing the spark and there still being some fuel in the cylinders …). The #3 plug was *way* better than I'd found it before cleaning it but it was clearly darker and wetter-looking than the other two.

I closed everything up and put the boat back on the mooring.

Any suggestions or recommendations?

[boats.net]

You should remove #3 carburetor again, you have missed a passage. Also start your carburetor adjustments at 1.5 turns out. Adjust each carb slowly and one at a time. adjust screw till motor lean pops then turn 1/4 turn in the opposite direction. Be sure to sync the carburetors.