57 18 hp Johnson missing

[jessper]

I went out snagging last weekend, and after running the motor at about idle speed for about 4 hours, it started running badly. It didn't seen to want to idle smoothly anymore, and kept sputtering at higher speeds. It seemed like it was flooding or something. I was running a 24:1 oil mix. Would this just be from fouled plugs? If so is there a plug I can use that won't have this problem on extended trolling? Or is this motor just not made for doing 4-6 hours of trolling at idle speed at one time? I just want to make sure that I fix the right thing, before I go back out on the water.

 

[wbeaton]

Re: 57 18 hp Johnson missing

Sounds like fouling. Your motor is meant to run Champion J4C spark plugs. You could try going to the J6C. Using synthetic outboard oil may also help.

 

[freddyray21]

Re: 57 18 hp Johnson missing

running at idle that long can foul the plugs. Changes the plugs and see if it still does it. If not then the plugs are the culprit. If so then you might have a coil going bad. Could be other things as well.

 

[rjezuit]

Re: 57 18 hp Johnson missing

It takes all of 2 minutes and 2 new plugs to change the plugs. If you continue like this, just change them before you head home. I know it sounds like a pain, but is a simple fix if the plug type changes /synthetic oil does not help. Clean the fouled plugs when you get home and swap back and forth between 2 sets. Rick

 

[jessper]

Re: 57 18 hp Johnson missing

I will try that. I already bought 2 new plugs so I have them, I just can't test the motor easily at home, and wanted to have everything I need to get it running right when I go back out on the water. Does the brand of 2 cycle oil matter much for fouling? I was using walmart super tech oil at the time. I have been using mercury oil previously. Would this make a difference. If neither is synthetic they should pretty much burn the same shouldn't they?

 

[wbeaton]

Re: 57 18 hp Johnson missing

Lots of folks run Wally World oil. I doubt its the problem. The synthetic oil smokes much less and doesn't leave an oily mess on the water. Its worth the extra $ IMO.

 

[tashasdaddy]

Re: 57 18 hp Johnson missing

those motors ran fast real well gapped at .030 but for extended trolling they advised opening the gap to .035 or .040 to reduce the fouling. oil is not the problem. some of the 57's did not have thermostats either. gap and cold running caused the fouling.

also this is from Joe Reeves, it is the best medicine for those motors. i used it on mine and never touched it again.

(High Speed Adjustments)
At full throttle, with the proper size screwdriver, slowly start turning one of the H/S needles in segments of 1/8 turn, waiting momentarily for the engine to respond, then repeat turning. You will reach a point where the engine will start to die out. At that point, back that needle valve out approximately 1/4 turn. Now, go to the other High Speed needle valve and repeat that procedure. At some point in that 1/4 turn out, you will find the smoothest high speed setting (you can now lower the throttle rpm). That will have both high speed needle valves set correctly, and at that point you can lift that center lever adjustment of that high ridge, keeping it lifted until the point is facing the engine, then lower it into its proper position. (When you turn that lever now, you're adjusting both High Speed needle valves at the same time

(Slow Speed Adjustments)
Now, lowering the rpms of course, take the engine out of gear and set the throttle just to where the engine will stay running. Again, in segments of 1/8 turn, slowly start turning in one of the slow speed needle valves, waiting a few seconds between each turning for the engine to respond. As you turn the s/speed needles in, the rpms will increase..... and as it does, lower the rpms to where the engine will just stay running (otherwise the rpms will climb quite high). You will reach a point whereas the engine will either start to die out or it will spit back (sounds like a mjild backfire). At that point, back the needle valve out 1/4 turn. Repeat the process with the remaining slow speed needle. Again, at some point in that 1/4 turn out, you will find the smoothest setting. When finished, tighten the jam nut somewhat, then remove and reinstall the s/speed knobs correctly (right side up).

 

[jessper]

Re: 57 18 hp Johnson missing

That makes sense. I didn't even think about opening up the gap to troll. I will make sure and do that next time. I already get enough crap about having a 50 plus year old motor, and anything to show them that it is just as reliable as a newer motor helps.

 

[tashasdaddy]

Re: 57 18 hp Johnson missing

properly cared for that motor will be around another 50 years. do Joe's carb adjustments also.

 

[jessper]

Re: 57 18 hp Johnson missing

Ok I will try the carb adjustments. I screwed with the idle and high speed adjustments on the front of the motor after it started running bad, so I have no idea how far off they are now. That will help get them set back to correct settings. Thanks for the help. If the rain holds off, I can get it out after work tomorrow, otherwise it may be next weekend.

 

[tashasdaddy]

Re: 57 18 hp Johnson missing

do those things you will have a motor that runs like new.

 

[jessper]

Re: 57 18 hp Johnson missing

I have replaced spark plugs, gapped them and rebuilt the carb with a new float and it still does it. I hoped it was the carb as the cork float was coming apart, but it still does it. The only other thing I can figure it might be would be one of the coils, as it seems to work better cold, and start doing it more as it warms up. Also when it does it it seems to happen for longer time periods when it is warm, and it keeps running rough, when runs good for a few seconds and then rough again.

 

[wbeaton]

Re: 57 18 hp Johnson missing

Is it a miss or a sneeze?

You may have a bad seal in the powerhead. Get a can of WD-40 or the like and start the engine up. I use aerosol 3 in 1 oil as its less flammable. When it starts "missing" spray all the seals and joints of the powerhead. Start with the seal behind the carb, then move to the intake gasket, then the crankcase to block joint, the upper crankcase seal, etc... Spray each one individually and methodically. Spray one seal/joint and wait a moment to see if the "miss" goes away. If not move to the next seal/joint. If this doesn't solve the problem then it could also be the lower crankcase seal, which can only be replaced by removing the powerhead.

 

[F_R]

Re: 57 18 hp Johnson missing

I have replaced spark plugs, gapped them and rebuilt the carb with a new float and it still does it. I hoped it was the carb as the cork float was coming apart, but it still does it. The only other thing I can figure it might be would be one of the coils, as it seems to work better cold, and start doing it more as it warms up. Also when it does it it seems to happen for longer time periods when it is warm, and it keeps running rough, when runs good for a few seconds and then rough again.

Have you even looked at the ignition? Have the coils ever been changed? Are the points dirty? You gotta get in there and fix it.

 

[tmcalavy]

Re: 57 18 hp Johnson missing

And after you resolve the miss, consider a hotter set of plugs for trolling...maybe bump to a J6C or J8C. J4 through J8's are incrementally hotter. You can also pull the plug wires one at a time when it starts doing this, if you get no apparent effect you have targeted a cylinder/coil.

 

[jessper]

Re: 57 18 hp Johnson missing

It is a miss for sure. It doesn't have a problem with sneezing unless I turn the carb adjustments down too much. I haven't looked at the points yet. That is my next thing to check. Is it possible to clean the points with sandpaper or something or should I just buy new ones?

 

[The-Machinist]

Re: 57 18 hp Johnson missing

I would almost put money on the coils. Go ahead and pull the fly wheel and inspect them. If they havent been replaced before, they need to be. I have a 1954 evinrude 15hp that was acting the same way, 50+ years on original coils was more than enough. I found a set here on iboats and she starts on the second pull(every time) and runs like a new motor again. I plan on giving it to my son in a few years. If your points are not burned badly you should be able to clean them with fine sand paper, but they are not that expensive and you might as well replace them as well. Also, How was your snaggin season?

 

[wbeaton]

Re: 57 18 hp Johnson missing

It is a miss for sure. It doesn't have a problem with sneezing unless I turn the carb adjustments down too much. I haven't looked at the points yet. That is my next thing to check. Is it possible to clean the points with sandpaper or something or should I just buy new ones?

So what have you done? I remember when you first got this motor we told you to inspect the ignition before running. And now you say you haven't even cleaned and set the points? Start from the beginning, what have you done?

 

[jessper]

Re: 57 18 hp Johnson missing

I didn't inspect the ignitinon components at first because once I got the fuel pump installed it ran great. I have since installed new spark plugs, and rebuilt the carb including replacing float. I have changed out lower end oil also. I will be pulling the flywheel off this weekend to see what is going on with it. Hopefully it doesn't get too expensive. Money has been a little tight lately.
Also I replaced the impeller.

 

[jbjennings]

Re: 57 18 hp Johnson missing

I believe you can get coils, condensers, and points for less than 100 bucks.
It's well worth it. You might get away with not replacing the points and condensers and just cleaning the points. Then just the coils would be about 50bucks. they're usually the problem. In every case I've had, a miss was caused by ignition. Coils specifically, but had 2 motors lately with a bad condenser. Annoying, but cheap fix.
Good luck,
JBJ