I have a 1976 Johnson seahorse 85 HP (1)-I can not get it to crank I have checked battery starter power packs fuses. (2)-It will turn over for a few seconds but won't run. I was told it might be stator but not sure I do know that (3)-every time you turn blows ignition fuse. Is there anything anybody can suggest I really don't want to take it to shop closest shop is four hours away.
1 - The term "crank" pertains to either having the electric starter turn the engine over (flywheel turns and pistons go up and down etc) or cranking the engine over via a manual starter or rope. Many boaters confuse the term "crank" with "start". I am assuming that you mean that the engine is cranking over but will not start... is this correct?
2 - Here, I assume that when you hold the key in the start position, the engine is cranking over but does not fire and run. That engine must crank over at least 300 rpm in order for the stator to energize the powerpack... Does it?
3 - And here you are saying that the 20 ampere power fuse blows every time you attempt to start the engine. This indicates that the electric starter is faulty and is drawing too much amperage. This is the first thing that you must correct due to the fact that the starter must be able to crank the engine over for a 20 second period... no longer than 20 seconds as that will cause the starter armature to melt the solder that holds the commutator together... what the brushes ride against.
To test #3... Have good known jumper cables attached to a good known battery and run the jumpers directly to the electric starter. Does the electric starter crank the engine over normally (Fast?)... let us know what you find.
With the spark plugs removed..... and when the engine will crank over fast (at least 300 rpm), check the compression. What is the psi readings of all individual cylinders? Then, with the spark plugs still removed, check to see that the spark is as it should be.
(Compression & Spark Test)
(J. Reeves)
1st - Regardless of what problem one might encounter, always start with the basic troubleshooting procedure. Check the compression which should be in the range of 100+ psi (somewhat less on the smaller hp engines) and even on all cylinders.
2nd - With the spark plugs removed, rig up some type of spark tester whereas you can set a gap to be jumped. On magneto ignition systems.... and also the Battery Capacitance Ignition system OMC engines from 1968 to 1972, set the gap to 1/4". On the solid state OMC ignition systems from 1973 to the present, set the gap to 7/16". The spark should jump the gap with a strong blue lightning like flame..... a real strong blue snap!
NOTE: Checking the spark via using the spark plugs is a waste of time and proves nothing. The above stated gaps must be used for a proper test.
If there was no spark, on engines from 1973 up (If the electrical plug exists), disconnect the RED main electrical plug at the engine. Remove the s/plugs. crank the engine via the starter solenoid (jumper bat term to small 3/8" term nut, not the ground nut) and observe spark. If spark is now okay as stated above, the usual cause is a shorted ignition switch BUT that black/yellow wire could also.be shorted to ground at some point wthin the wiring harness.
For the later model engines where that large RED electrical plug was discontinued for updated electrical connections, find the black/yellow wire leading to the powerpack and disconnect it to run the above ignition switch/wiring harness test.
If the above checks out as it should, and the engine dies out when throttle is applied or won't idle, it is usually due to one or both of two things. The carburetors are fouled, in which case the cure would be to remove, clean, and rebuild them..... or the timer base under the flywheel is sticking which would result in a retarded spark. If the engine will not fire/start at all even though you have the proper spark and compression, it's usually due to fouled carburetors.
To check the timer base for sticking (Engine Not Running), spin the prop to align the shifter dog with forward gear and while doing so, put the engine into forward gear. Now, while watching the timer base, slowly apply throttle clear up to full throttle. The timer base should move smoothly all the way up against the black rubber cap that is atached to the end of the full advance spark setting screw. If the timer base sticks, find out why and correct that problem.
Usually any sticking of the timer base is caused by one of the four retaining clamps being slightly too tight. Putting a very thin washer under the clamp cures that problem. Some boaters use a thin screwdriver to bend the clamp upwards slightly but I prefer the thin washer. The sticking can also be caused by having a faulty stator start to melt down, resulting in a sticky substance dripping down on the timer base nylon retaining ring.
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(Spark Tester - Home Made)
(J. Reeves)
You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:
A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
..........X1..........X2
.................X..(grd)
..........X3..........X4
