coil question

geb

Seaman Apprentice
Joined
Jul 24, 2007
Messages
37
I did an ignition coil test with an ohm meter and found that #1-5 coils from tower to + or - gave a reading between the 8-11 rX100 reading (9) specified in the manual. However the #6 coil gave a reading around 3.5. What effect would this have on performance? I'm having problem with getting to plane without giving very very slow throttle, and even then it may not get enough power to even go. It chokes and and fights to keep going with the throttle. It will however crank up and idle with no problems whatsoever. I'm getting steady spark to all the plugs according to my timing light, but I don't know how strong of a spark on that #6. I don't own a spark tester so I'll check with 1/4 in gap to ground to see. The #6 plug seems very clean as opposed to the other 5 plugs which show signs of gas/oil/carbon?(blackness) after use. Also, does anyone have any suggestions on why my speedometer would not be working? Could the tube running from the LU to the tack be clogged or something? I'm not really sure what that tube does for it, pressure? Anyway, thanks for any assistance.

merc 140 ser #574...

geb
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: coil question

geb, It sounds like #6 coil is bad. Swap with a known good one and see if it improves. A clean #6 plug could be water ingestion. See if you see little drops on the plug, after a run. It could also be a bad fuel pump diaghram.
 
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