I am looking for some advice on a Mariner (93) 25 horse motor. I have been troubleshooting this no spark condition on this motor and have checked my stator and trigger (resistance test) and both check good. I have absolutely no spark from either cylinder. I then disconnected the black/yellow wire from the switchbox to the ignition. When I cranked the motor, I got spark on both cylinders. The black/yellow wire is the ignition stop wire. Could this be a problem with my ignition switch? My thinking is that if I get spark, the coils, trigger, and stator are good?? I am guessing I am down to the ignition switch or the switchbox? Thanks!
fishguts,Firstly, thanks for all the right info and the checking you've done up to now. It gets quite frustrating on this forum trying to help people who say "My motor doesn't work".If you have disconnected the blk/yel wire and now have spark, the switch box is good. Just check that the lanyard is still in the safety switch on the control box. I know it's obvious, but you'd be surprised how many people overlook it. Chris........
__________________
The world takes on a whole new perspective when viewed from 100' below...
1972 Bertram 'Bahia Mar' 20
2006 Mercruiser 4.3MPI (OW617679) w/Alpha 1 Gen II (OW829301)
Achris60, thanks for the help. I have checked the lanyard switch. I am going to try to bypass that today to make sure it is still functioning. The previous owner has been in there (wiring) and it appears that the switch may be able to be hooked in a normally open or normally closed position. I am also going to see if that was switched around and could just be in the "off" position. Thanks again for your help. I will let you know if I find anything.
ok... switch update. I made sure the tether switch was operating normally. As I said in the earlier post, I disconnected the stop switch and got spark. I bypassed the black/yellow wire and plugged directly into the harness to make sure I didn't have a broken wire under the floorboard. With that "new" wire in place, I still have no spark. I guess now I start with an ignition switch???
fishguts,Sounds like you trackin' along nicely. Good luck and keep us informed.Just one question. This 25hp, is it remote control and electric start?Chris..........
__________________
The world takes on a whole new perspective when viewed from 100' below...
1972 Bertram 'Bahia Mar' 20
2006 Mercruiser 4.3MPI (OW617679) w/Alpha 1 Gen II (OW829301)
Sorry, it's a remote control electric start. I replaced the ignition switch. That means I have to have a problem somewhere in the tether or a ground in my stop circuit. I am going to make a test wire from the motor to the key switch and back through the tether to ground. I don't know if my tether is suppposed to be normally open or normally closed. It's not published on the schematics I'm using either. So, I am looking for an out of place wire or a bad tether at this point. I will let you know if I find anything. Thanks again for the help, I really appreciate it.
The kill switch is a normally closed switch(Held open by lanyard) and when the lanyard is pulled out of the control, ground contact is made to the ignition switch and on to the engine. The kill switch is directly related to the ignition switch kill circuit. Sounds like the kill switch is your problem. Check for continuity between the kill switch and the ignition switch terminal. As you said,
Ok fellas, I traced the circuit for the stop switch on that Mariner. I noticed I had a large loop of wire that came out of middle of the wiring harness (Black/yellow). I followed them and they both plugged to ground on the firewall. I unhooked one end, now with everything (tether and keyswitch) in the run position, I get spark. When I unplug the tether, it goes away. Imagine that! Is it safe to say, that there probably was some sort of switch that was once wired or that a different tether in a normally open state could have been used in place of the one I have? Everything seems to work.. I can't imagine I would have a problem where I couldn't stop the motor, the tether seems to be doing it's job.. What do you think? I thank you all for your help!!
One thing you might want to check is the mercury switch as it is wired in conjunction with the kill switch. It is mounted on the egine at an angle, with a black /yellow wire coming out of the top, so that if the engine is tilted up too high, it will not let the engine fire. They don't usually go bad but you never know. I would double check before you purchase the kill switch. From you description, it sounded as though you were by-passing it.
25 hp Mariner, no spark! Switch problem?
My thinking is that if I get spark, the coils, trigger, and stator are good?? I am guessing I am down to the ignition switch or the switchbox? 
Thanks!
your help!!
Linear Mode
