merc 7.5 no spark on 1 cylinder

[albertaborn]

so ive just noticed one of my cylinder has no spark.i am talking about a merc 7.5 hp 7155910 outboard.so i switched the leads going to the cdi(or coil) unit and the was spark. so the coils must be good.this leads me to beleive the ignition unit is pooched. its the same ignition for both coil and both coils work but just off the one feed. so must be something inside the cdi. unless there something i dont know about this thing only kicking in the next cyl at a specific rpm but thats crazy talk. any help ?

 

[albertaborn]

Re: merc 7.5 no spark on 1 cylinder

so here is a microfiche of the parts to follow along http://www.boats.net/parts/search/M...P/FLYWHEEL AND IGNITION COMPONENTS/parts.html

i am talking about the switch box is what the proper name is i referred to it as cdi box before but still i switched the wires around to check the ignition coil and the coil work.so i took my multimeter and set to ohm 200k to see if there was any dif in the two set of leads to the ignition coils, and the set that dont work read 7.8 k and the set that work 10.8k. is there any thing else i could try to confirm its the switch box.so the switch box has these here wires; orange wich attaches to the coil assembly # 7, black for ground, and two for the coil triggers, then the four wires for the ignition coils.any ideas guys you guys are the pros help me out before i go stir crazy lol

 

[verado7]

Re: merc 7.5 no spark on 1 cylinder

yeah if you switched the wires around and the spark followed - definately the switchbox

 

[albertaborn]

Re: merc 7.5 no spark on 1 cylinder

so it was the damn switch box. i got a used one from marine madness in edmonton ab. i think im getting close for a maiden voyage since a new piston, impeller,gasket,and now switch box.thanks for your reply this site rocks.just need the ice to melt