'88 Merc 15 hp kicker ignition problem

[scook]

With fresh gas and standing in a large pool of sweat from cranking I finally got the motor started once. It seemed to run up OK, but was in a garbage can of water and didn't want to flood the shop, so didn't rev it up too much and shut it off fairly soon.


I think I have it diagnosed, but am hoping I'm wrong.



One coil sparks when cranked and the other doesn’t. When the primary leads are swapped, the other coil sparks and the first one doesn’t. Looking up under the flywheel, there’s no rust or crap of any kind to interfere with the coil/magnet interaction (it's a very clean looking engine), and the stator & trigger coil resistance checks out OK.


I went through the diagnostics in the manual that I was equipped to do (resistance of all of the coils) and with one exception, the resistance readings are all in spec. The only ones out of spec (by a factor of 10, which I think could be a typo) are the secondary coil readings (manual says 8-11,000 Ohms and I get 906 on both coils), but I don’t see that being the problem, since both coils make a good spark when driven by the good primary lead.


This seems to leave only the switch box (electronic ignition module) as the problem. A quick check shows that to be a $175 – 200 part.

If there’s something I’m missing, I’d like to know what it is – this is a friend’s motor he’s willing to sell to me at a reasonable price if I can get it working, and I’d like to avoid taking off another $200 if possible.


Specs, in case I need the part and one of you guys has it and my friend goes for the deduct:

Motor SN: 0C114352
Switch box part No.: 339-7452 A10


Thanks for any help - Scott

[bigshrimpin]

http://www.ebay.com/itm/Switch-Box-f...749974&vxp=mtr

Plenty of options for you on ebay. New ones for around $100.