after 2 min of water time my engine has a real bad miss and sounds like a cylinder down,,,its old im told it has point most likely ,,,is there a expert on johnson or recommend any out west for a water test run ?
m16d,
Jan 31, 9:58am
Crikey it must be ancient if it's got points. Change the plugs,and check the leads for cracks is what you should look at 1st.
elect70,
Jan 31, 10:03am
Start with new plugs & compression test ,check igtn leads & connections , 1 good thing is parts are easy & cheap to get direct from johnson in USA no matter how old it is just give them the serial # & they can tell you its build date etc . Look up the service manuals for it on line . Some faults only become apparent when under load at full throttle .
bwg11,
Jan 31, 11:08am
If it is old enough to have points, it will have two sets, two coils and two condensers, all under the flywheel. All of these will need checking, but look closely at the high tension leads where they bend as the magneto base plate moves as the throttle is opened and closed. The leads often fail at this point.
ambo11,
Jan 31, 11:35am
If its a really old one, one of the coils is probably shot. Johnson ( originally made by OMC I think) used the same coils in the small outboards, as they did in the old 2 stroke iron horse mowers, the really old ones before the common D series which has a different coil. The crack and break down, easily replaced and about $20 ex USA from memory. Would need to be an old outboard though.
snoopy221,
Jan 31, 1:49pm
Ya lucky ya got one of THE BEST out your way. Glen west auck marine corner of Hepburn and Akatea.
402rat,
Jan 31, 8:20pm
thanks all i have done comp test and is fine and new plugs also,diaphragm has been out and checked seems since i replaced its got alot worse . but i do remember out on water last year this same miss would happen but once or twice over few months not after 1-2 mins on the water like now,,
Looks like wires going to points under the flywheel, give them a clean, check gap and clean all connections.
bwg11,
Feb 1, 5:00pm
From your pics, I'm almost certain it is a 1987 model. Disregard my comments at post #4. Being 1987, it will be CDI ignition, not magneto with points. Probably best to get all components checked by a competent OMC technician with the correct test gear, in preference to random swapping of components.
This is what your ignition system should look like.
I eventually yanked the flywheel off my 15hp Johnson. 1975 model, to find the points were a mile out! Also the magnets were all rusty. Gave the whole lot a clean, readjust, to as new specs. Still to get it wet. And then fitted new coils.
402rat,
Feb 2, 3:45pm
how do i identify motor for specs?and cheers for info ,,was your playing up like video
Watching your video, it is not going out on one cylinder, but the whole ignition system is cutting in and out (just like turning the key or kill switch off and on). I would be looking at your remote box, wiring and components common to both cylinders. As dave653 says above, there should be a ID plate riveted to the transom clamp assembly, but from the decals I still think it is an 1987 model.
mainlander05,
Jul 9, 8:05pm
Be carefully as I twice had a Marine shop diagnose CD unit at 360 bucks and they were both wrong.it was the advance plate had seized.only when I sent CD units to be repaired the fix it guy rang a d said they were OK.he was honest.lucky for me.
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