1984 johnson 70hp that wont fire 1 year old on stator and powerpack been running fine?

Question

getting fuel , got 125 on all cyl .allready check the lanyard . dont run champion not worth a flip , 50-1 got it , not getting spark out of coil

Answer 1

Reattch the emergency lanyard & try again.

Back to basics:  3 things the motor needs:  compression, spark, fuel.

Compression gauge, around $25, look for even compression, lowest within 5 or 7% of highest, 130 PSI or better would be outstanding, anything better than 100 would be acceptable.

Cranking RPM -- needs to be at least 250 RPM to generate spark.

Spark test (not a "spark plug" test), use an inline tester to test whether the ignition is capable of generating spark.  Set the gap for 7/16", clip it to the engine block, attach spark plug leads (one at a time), look for sharp blue spark while someone turns the engine over with the key.

Good compression & spark on all three cylinders, then put some 50:1 premix fuel/oil in a spray bottle, spray it into the carb throats & try again -- does it sound like it's trying to start?

What do the spark plugs look like after cranking?  Wet, dry, fouled?  Does one look different from the other two?  Are they champion QL77JC4 gapped at .030?

Report your results.

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Your motor was designed around champs -- like it or not, that's what it'll run best on -- I get 2 or 3 years from a set of champs in my '79.  Whatever you decide, be advised that  the NGK equivalent is not an exact match for heat range.

Any case, no spark on any cylinder, first rule out kill circuit by disconnecting black/yellow wire from the powerpack & retest.  If you get spark now, troubleshoot keyswitch, kill switch & wiring.

Next disconnect rectifier & retest.  Get spark now, replace rectifier.

Measure the stator resistance & DVA output (powerpack connected), brown wire to brown/yellow should be 450 to 550 ohms, and at least 150v peak AC.   Any other result means bad stator.

Measure timer base resistance & DVA output from the white wire to purple, white to green and white to blue.  Each case, you need 38 to 42 ohms and at least 0.6v peak AC.  These are the specs for motors without "quick start".  Any other result, replace timer base.

DVA output from the powerpack on the orange wires while connected to the ignition coils needs to be at least 150v, else bad powerpack.

All checks out ok, pull the flywheel & inspect for loose, shifted magnets.

If you can measure any voltage at all on the black/yellow wire, that'll cause repeated powerpack failures.  Cause is a wiring fault -- missing/chafed insulation allowing stray voltage on the kill circuit.

Answer 2

Need some more information other then it won't fire.Does it have spark?Is it getting fuel?Be glad to try and help but I need

more information.