This is an engine I purchased on ebay (NEVER AGAIN !!!) to put on a boat I was rebuilding. It's had multiple issues which I've fixed one at a time, but this latest has me stumped.

It's done the same thing to me the last two trips to the lake - starts up ok, idles out of the no-wake zone ok, run around for 15 or 20 minutes with multiple stops and starts including a few WOT runs - still ok, and then all of a sudden it won't stay running at idle and bogs coming out of the hole. To keep it running at idle I have to keep my foot in the throttle, and even then it idles really rough and frequently dies out (make it real fun putting the boat on a trailer at a crowded ramp!).

It has a new CDI power pack and new CDI timer base (which I re-tested this weekend per OMC service manual procedures and they check out ok). The stator charge coil resistances are 734 and 767 Ohms (spec. is 985 +- 25 but I'm thinking the difference may be because I'm using a Fluke and not an analog meter - feel free to disagree with me), and the charge coil cranking outputs are 183 and 188 volts (measured with DVA adapter), spec. is 130 volts minimum. All 6 coils check out ok on the resistance test.

edit to add: I put in all new spark plugs before the last trip to the lake and pulled them when I got home. They all looked the same, insulators were slightly brown - about what you'd expect.

What am I overlooking? Thanks in advance for any and all expert advice.




Modified by groundloop at 8:13 AM 5/2/2011