3rd cylinder not firing.

[Chuckpan]

Hi. I have an 06 Mercury. 3 cylinder 2 stroke outboard. When I pulled the plug wires one at a time, I found the bottom cylinder didn’t change the idle. I pressure tested all the cylinders and they were from top Dow , 120, 119, 120. Just wondering what I could do next to fix this problem. Thanks Chuck.

 

[racerone]

No spark.----No fuel.-----No crankcase compression on the #3 cylinder.

 

[Chuckpan]

Haven’t checked for spark yet. Compression turned out to be ok

 

[Chuckpan]

Carb slowly leaks from pin hole in air intake.. Cleaned carb, and re adjusted float but doesn’t stop slow leak.Fuel seems to be slowly leaking fro the carb from the pin hole in the throat of air intake

 

[Chuckpan]

Haven’t checked for spark yet. Compression turned out to be ok

Yes it has spark

 

[Chuckpan]

Yes it has sparkjust wondering how to proceed.

 

[fastjeff]

Sounds like the lower cylinder is flooding enough to foul the plug. Need to rebuild the carb and stop that leak.

Jeff

 

[Chuckpan]

Sounds like the lower cylinder is flooding enough to foul the plug. Need to rebuild the carb and stop that leak.

Jeff

Thanks Jeff. I've already cleaned that carb but possibly didn't do sick s good job. I'll try it again.

 

[racerone]

Does the spark on #3 jump an actual 3/8" gap on a test device, yes or no ?----Have you checked crankcase compression ?-----And no fuel or too much fuel could still be the issue.

 

[Chuckpan]

Did not check came case. Don't know how. Decided to drop it off at the marina and let them deal wit it. I think it's over my pay grade. Thank you for all your help. It got me this far and I learned a lot. Thank you.