One cylinder cutting out intermittently - 1996 Evinrude 9.9

1996 Evinrude 9.9 HP, tiller, manual start, short shaft.<br /><br />One cylinder goes out intermittently. Appears to be an ignition/electrical problem, since it is the same cylinder that goes out (bottom cylinder), and it never sputters or does anything that would indicate fuel or carburetor problems. I have rebuilt the carb and changed the plugs since this problem started, and neither made any difference.<br /><br />The details:<br /><br />It doesn't sputter. It will run solid on either 2 cylinders or 1 cylinder, and it will run in either condition for anywhere from 1 minute to 30 minutes (or more).<br /><br />After a cold start, it may run fine for 5-10 minutes, then one cylinder quits for 5-10 minutes, then it might kick back in, might not. <br /><br />Sometimes it will only run on the one cylinder after a cold start, but then the second cylinder will kick in after 5-10 minutes. <br /><br />There does not seem to be a correlation between engine temperature and the cylinder cutting out.<br /><br />I have replaced the ignition coils, and it has not made a difference. My next guess is the stator or the power pack (CDI unit). These are both higher cost items, and I would like to narrow down the problem, with your help. I don't want to slap a new power pack on it only to have it fried by a bad stator.<br /><br />Any ideas? How to check the stator?<br /><br />Thanks for your time.

Re: One cylinder cutting out intermittently - 1996 Evinrude 9.9

Use an inline spark tester while the motor is running and notice spark "gaps" or misses.This will give you a better idea if its ignition or fuel related.Like you mentioned it could be a stator/trigger problem or maybe the ppack is going bad.

Re: One cylinder cutting out intermittently - 1996 Evinrude 9.9

Try cleaning the coil grounds.

Re: One cylinder cutting out intermittently - 1996 Evinrude 9.9

Thanks for the advice.<br /><br />FYI - I replaced the power pack, and it's running like a champ.