No fire on Cylinders 2 and 5

[gdawkins]

2001 mercury 240 m2. Lost power while running at the lake. Brought home, changed plugs, and checked spark plug fire ( with in-line spark tester). I have no fire on cylinders 2 and 5. (Top cylinder on port side and bottom on starboard side). I am not sure if there is anything relating these two cylinders together.

 

[gdawkins]

I think I found the connection.... Trigger coil. Now to look for tests.

 

[gdawkins]

Ok. I found this on another forum about how to check the trigger coil: Check the trigger coils resistance, Red to white, Blue to purple and Black to yellow all should be 1100 to 1400.

My my readings were around 1200-1300 on blue to purple and also on black to yellow. I had no reading on red to white. Also, the coil was cracked on one of the tabs on the trigger coil. I am assuming this is my issue and will order the trigger coil.

If someone finds that I need to do some other tasks let me know. If there is a cause that might have caused this to fail or if I need to replace something along with the trigger coil.

 

[Ken Inman]

I had exactly this happen on a Merc Sport Jet 175hp, it was the trigger assembly. On page 2A-11 the manual states that if two cylinders on opposite banks lose or have weak spark then suspect the trigger. the troubleshooting guide for this is on page 2A-15 in the manual. The trigger assmb was not that expensive and is easy to change but I had to buy a special tool to pop the flywheel off.

Manual - http://boatinfo.no/lib/mercury/manuals/210_240_m2jetdrive.html#/68

Puller & lift eye - http://www.ebay.com/itm/371049441569?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

[Coastiejoe]

I think you are in the right area based on what I have read. Dr Honda would know for sure...

 

[Dr Honda]

I always like to see when members figure thing s out on their own.


But you hit it right on the head. 2 and 5 share a trigger. You test shows the trigger is bad.