1983 Mercury 80hp coils question

Hi all! New to the forum here and have a question about the ignition coils on my '83 80hp Mercury. I tested the coils according to the manual test. I used a Cen-Tech multi meter. Set it to 200 (lowest setting) for the + to - post check and get .7 - .8 readings on all 4 coils. Testing across to the coil towers I get 923 on #4 and 952 - 956 on #1 thru #3 with the meter set at 2000. According to the specs the + to - are not good? Should these coils still need to be replaced? If so are the Sierra replacements any good?

Charlie

Not likely that you have 4 bad coils.------What other trouble shooting have you done ?------What is the motor doing / not doing ?

Hi racerone and thanks for the reply. It idles well in the water. Seems to be a bit cold natured so I let it warm up for a few mins before taking off, otherwise it will sputter out when I put it in gear. Even after warm-up it doesn't want to idle in gear so I have to throttle up a bit immediately. On going full throttle one cylinder has a miss, it will eventually catch and fire normally. I'm hoping to get some dry weather with the warmer temps setting in so I can get the timing set. Have to reset the pointer since pulling the flywheel and replacing the trigger and stator assemblies. Once it's been run for a bit it will idle in gear. Just trying to go through the process of elimination to tweak it out of being so cold natured. I have pulled the carbs, cleaned and reset the idle screws. The motor runs great with just muffs on.. but there's no load so I don't count that much. I plan on replacing both the plugs and wires this spring as well. Maybe that's all it needs and this is for naught but thought while I had the chance checking the coils couldn't hurt. Was just concerned about the + to - post results.

Post the results of a compression test.-------I do not believe that motor has a thermostat so in cold water it barely warms up.----You may just need to open low speed mixture needles a 1/4 turn at a time to get rid of the stumble on acceleration.----And you run with a timing light to see how ignition behaves from idle to full throttle out on the lake.----Test one cylinder at a time.

Your coil readings are close and not the problem unless its cracked and arcing thru. Miss is most likely trigger or switchbox problem.

Will definitely do the compression test. The boat and motor were purchased by an Uncle, now deceased, and has been in the family since. My brother recalls it being cold natured even back then. Likely because of not having a thermostat as you said racerone. I'll keep tweaking it. It's not a bad motor overall... and I certainly can't afford a newer one. lol Thanks for the reply.

@faztbullet I was concerned for the readings because Mercury said they should be .2 to .4 and my results were twice that. More concerned as to the strength of the charge being delivered. The trigger and stator assemblies are brand new and the switchbox was tested w/no problems at the time of installation. The tower on the #3 coil does have a chip out of the top to the outside. Due to its orientation though I don't believe that it's arcing out, plus the miss disappears after a short bit at full throttle. I really appreciate the reply.