Problem child Merc 15

[hondon]

Merc 15 electric start came to me new to the owner with no start issues.Copression was as expected about 120 per,ignition output was intrermittant .Troubleshot that down to poor swithchbox output to the coils.Changed the pack and output was ok.Put it in the tank and the engine would only run primed or prompted by starting fluid.SOO the service writer suggested to the kid that owns this engine that he buy a new carb and install it himself.Of couse it came back to me with the battery cables reversed and after I figured that one out ,NO SPARK!!!The kill switch is disabled.Troubleshot that again down to NO pack output to the coils but plenty into the pack.Sator output is to spec but on the low end and recieved a faulty new stator from Merc that sent me further chasing my tail.Installed new pack to no results .Reinstalled old stator and now have very weak spark in my opinion[1/4 inch on stevens spark checker when these things usually light up a dark room at 1/2 ].Trigger output is good as well.Ica'nt find any continuity problems to ground.This is a really simple ignition system so I may well be overthinking but it's kicking my *** nontheless.

 

[Ram57]

Re: Problem child Merc 15

If you have good output coming from condensor charge coil 100-300v and triggers >.3v into your powerpack with about the same going to your ign coils but have week spark or no spark then i would consider the ign coils themselve. How is primary and sec resistance on the coils? I would test voltage with a PL-88 and see how that reads. If your numbers are still good after that then the ign coils are bad. Hope this helps

 

[hondon]

Re: Problem child Merc 15

Thanks, never considered using the PL 88 as that is kinda an OMC thing but I will certainly see what numbers this thing throws at me.Acutually ran this unit this afternoon after changing in yet another stator.Ran great but while trying to sync everthing everyone else has done to this the engine stalled and will not restart.Hopefully just a little lean.Spark is still a little cold.3/8 is the best it will do consistantly.That's not enough for me as this is a pretty hot ignition ordinarally.Thank you for the feedback and by the way serial #is oc128622.I should have provided that with the original post .Thanks again.

 

[rdnk_4_lf]

Re: Problem child Merc 15

please dont spray starting fluid into the carb by doing so you can fry the cylinder seat the rings and have a huge problem on your hands just to have the rings redone costs about 400 $ so DONT USE STARTING FLUID !!!!!!!!!!!!!!!!

 

[hondon]

Re: Problem child Merc 15

I agree wholeheartedy,but from time to time you have to do things to these machines that you are not entirely comfortable with just to get to square one.I am not keeping it running with starting fluid.Just seeing if there is any change in this units reaction with it.Sometimes you gotta do what you gotta do.