fish good rocks bad

[fitz73222]

Look for coils/wires arching to the block; a very common problem and cause for a miss. Trying running her at night for a minute and see if she lights up like a christmas tree around the coil cores. I never seen an older OMC that the coil housings didnt crack eventually and start "leaking" spark to the block. Get some insulated plastic spark plug wire puller pliers from the auto parts store and start pulling wires one at a time while she is running until you find the miss. Two things will happen; the miss will go away or the engine may actually start to run better. Keep the wire boot near the plug while doing this and you will hear the arching. If the engine runs better when you do this, chances are the plug is bad and unable to fire correctly internally until you introduce an artificial gap.

[seagate]

Thanks for the tip I will get the spark plug pullers and try that I have a coil from a motor that was being parted out if I need a replacement.

[akbridge]

Did the miss start as soon as you removed the lower unit?  Just a thought, but an engine will run differently when out of the water and without a lower unit.  If there is less back pressure it will cause a lean condition that will cause the engine to sneeze and miss some.  Before you tear into the carbs and replace a bunch of electronics, bolt it back together and see how it runs.

[seagate]

It was missing before that was part of the reason we grounded.
When I ran at night there was no arking until I pulled the plug then it would ark all over the coils on all plugs.

[RebelYell]

..I started her sunday and she ran fine for about 5 min.then it started missing this is with fresh gas.It would miss then run fine then start missing again I will start looking in to this problem next weekend any thoughts would help.
Thanks

Power Packs ?

Mine ('90 150HP Mariner) did the same thing when I had one go bad. After much searching and haggling on EBay I just went and replaced power packs, stator, and voltage regulator a coupla years back. Found a "new old stock" OEM stator for $100 !!!

Anyhow, I don't have any spark / charging problems anymore.

 :joker:

[seagate]

I replaced a power supply and that stopped the missing the motor is running good now.I picked up lower unit from a old evenrude 175 I found in miami I have to check it out.Skegs bent have to look inside this week.How do you get stickers and stuff off the cowling so I can paint it I will need to paint the whole motor Lower unit was painted a gold color I would like to clean up the motor with some paint.Then I can put her back in the water.