no spark, still smoke a bit? merc '90 115hp o/b

joeboater7

Cadet
Joined
Apr 23, 2012
Messages
27
Last year swapped out all 4 coils, plugs, plug wires, and carb rebuilt. Engine was still half power, check spark and had 2 cylinders not sparking, so I changed out the powerpack for a cheapo from amazon. Worked great all summer.

Fast forward to yesterday, we took out the boat for the first time this spring and it started up immediately and ran perfectly. Got up to speed, ran around the lake, then put it in idle for a few minutes to see if it ran smoothly, which it did. Turned it off. Connected a few wires for the humminbird network switch behind the wall behind the throttle/start box. Then 20 minutes later went to start the motor and it turned over fine, but sound like no gas. Thinking that is odd, we usually don't need to pump the ball again, but tried that, still turned over strong, but not pops of ignition that I could hear. I pulled off the spark plug wires 1 at a time and held them near the spark plug to see if I could feel or see a spark jumping.. and saw none. So I think I am getting zero spark.

but.. the many times I kept trying to turn it over, I did see just a very small puff of smoke. Could a motor with no spark ever smoke even just a little??

Took it home, swapped power pack to a cheap amazon spare I purchased last year and tried again, still ingition although it turns over. Pulled the kill switch cord to trigger the switch, and tested turning over ... it still turns over.. is it supposed to do that? Put kill switch back to run mode. Jostled cables, messed with key, wiggled shifter, nothing helps.

main question, does that super small bit of smoke I sometimes saw when turning over indicate a stray spark? If so, maybe I should try a new/better power pack. But if a super small bit of smoke is possible without a spark, maybe I have some other issues.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
29,551
Charge the battery.----Clean the connections.-----Load test the battery.----Inspect starter motor internals.-----No money spent things to do.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
29,551
Time for more trouble shooting.-------Ohm check on stator and trigger unit.
 
Top