Weak spark

blacktrain

Seaman
Joined
Jul 20, 2013
Messages
59
I have a 1995 Johnson 40hp Model # J40ELE0 Serial # G03743175 following up from another post, with the plugs installed in the motor the spark gap is less than 7/16" it's more like 1/8". The compression is 180lbs. per cylinder, have fresh fuel, new plugs, flywheel key is good, battery is 13.36 volts, starter draw is around 100 amps. The motor will try to fire off but won't stay running. If my problem is weak spark, what would I replace? Stator, Timing base, Coils, etc. I have no idea what to replace. Thanks to everyone who has been helping me with this, i sincerely appreciate all the help.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,540
You have claimed that your starter is cranking it over " just like new "-----Myself I would take it apart for inspection.----No coins spent and easy to do.-----I install new brushes at $4.50 a set.----Get battery load tested too.----Often done for free at auto supply stores.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,411
180psi of compression would have me checking your gauge
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,694
what is wrong with trying a different gauge ? 180 is the highest # I can remember reading about on this site

if correct then nothing is wrong
 
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