1969 Johnson 115 erratic spark problem

dmhfab

Cadet
Joined
Jul 28, 2019
Messages
13
If the plugs are out the motor, it shows spark on all 4 wires when cranking it over and using a spark tester.

Reinstall plugs, and start the engine, 1 and 3 have show no spark when hooking a timing light around the wires.

Motor has a new cdi pulse pack, new spark plug wires, new distributor cap, rotor button is still old.

Thought it may be a issue with the pickup sensor on the timer base but it checks fine with an ohm test. Tried adjusting the gap down further between the sensor and timing rotor but that resulted in spark on only 1 cylinder when running. Opened the gap back up and back at the original spark on only 2 cylinders.

Started it at night and do not see spark shooting anywhere.

Any ideas?
 

dmhfab

Cadet
Joined
Jul 28, 2019
Messages
13
Sensor air gap should be 0.028".

Correct, that is what it is set at the best i can tell with feeler gauges. Tried a smaller gap but that did not help so set it back at 0.028". Still no fire on starboard side 2 cylinders.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,902
How long have you owned it ?----Did this problem show up suddenly ?----Part # of the distributor cap ?.------Where did you order the cap from ?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Are you trying to run surface gap plugs? Trash those things and put in a set of QL77JC4 plugs. Rationale? Plugs may be requiring too much voltage, causing spark to jump to the adjacent bar in the dist cap. Hey, might not be the solution, but certainly a cheaper guess than replacing pulse packs.
 

dmhfab

Cadet
Joined
Jul 28, 2019
Messages
13
How long have you owned it ?----Did this problem show up suddenly ?----Part # of the distributor cap ?.------Where did you order the cap from ?

Owned it since 1972. Has not been used for the last 4 years. Removed it to paint the boat last year. Reinstalled it, found the power pack had broken. Replaced the power pack, distributor cap (rotor button is still old), rectifier, plug wires, rebuilt the carbs while it was off the boat.

Distributor cap part number 383522. It is original OMC part.
 

dmhfab

Cadet
Joined
Jul 28, 2019
Messages
13
Are you trying to run surface gap plugs? Trash those things and put in a set of QL77JC4 plugs. Rationale? Plugs may be requiring too much voltage, causing spark to jump to the adjacent bar in the dist cap. Hey, might not be the solution, but certainly a cheaper guess than replacing pulse packs.

Yes have champion 827M in there. Did not know if it required those for piston clearance? Will the ones you listed work fine? At what gap?

Thanks.
 

Tim Frank

Vice Admiral
Joined
Jul 29, 2008
Messages
5,346
Oh man....the "new and improved " numbering system....:(

Be careful of those....have a friend who got really turned around by this. Some on-line retailers show vastly different combinations. Depending on where you look the 827M can br pictured as gapless ~ OR ~ conventional gap plugs.
 

dmhfab

Cadet
Joined
Jul 28, 2019
Messages
13
Oh man....the "new and improved " numbering system....:(

Be careful of those....have a friend who got really turned around by this. Some on-line retailers show vastly different combinations. Depending on where you look the 827M can br pictured as gapless ~ OR ~ conventional gap plugs.

The ones in the engine currently are gapless.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
What I said about surface gap plugs. What a farce those things were.
 
Top