1998 Mercury 9.9 Starting Problem after warm

S/N 0H0XXXXX

It all started with the motor not idling. Rebuilt the carb and cleaned several times. It got better but would still surge and not hold idle. Replace fuel filter, plugs, new electric choke and rebuilt the fuel pump. No change.

Took it to the Mercury dealer who went through the carb and ultrasonic cleaned it. Idles great, starts first pull and runs out good.

Took it out this weekend and problems started again. Around 2 minutes into back trolling above a rapid the motor abruptly stopped. Pulled and pulled but would not start.

Played with it an hour or so later and it started and ran fine.

I can recreate the problem by starting the motor and running it full speed for a couple minutes. Immediately cut the throttle and the motor dies. It will not start no matter what I do. I can pump the carb and hear fuel. Pull with the carb wide open etc and nothing. I did not check spark on the river but I'm guessing it has to be spark related.

Any input. Plan on getting to the no start condition and ohming out the coil(s). Other thoughts?

Re: 1998 Mercury 9.9 Starting Problem after warm

Primary I get .2 to .3ohms. Secondary is measuring open on either plug wire. Plug to plug is 14.5k ohms.

Re: 1998 Mercury 9.9 Starting Problem after warm

I was chasing a problem like this and I bought one of those inexpensive tools from the auto parts store that connects between the plug wire and the plug. It makes it easy to see if your plug is firing. For only $5-6 it will get you a step closer to closing in on your issue. Good luck! Sounds spark-related, and possibly the stator rather than the coil.

Re: 1998 Mercury 9.9 Starting Problem after warm

anyone happen to have the resistance specs for the ignition circuit on this motor? I don't have a shop manual for it....yet