Coil Pack? Advice needed

need a bit of advice regarding coil packs in my 70hp Johnson 2 stroke.... here’s the story

headed out last night and at the boat ramp the engine was running real rough and Smokey. As I had just changed the spark plugs I had the old ones with me so swapped them back over, made no difference. Checked the spark by pulling the lead of when running haha. The top one shocked me hard, middle one didn’t shock me at all, bottom one shocked hard again (good way to test I know haha) swapped leads over and made no difference. Mucked around for a bit checking coil wiring and swapping spark plugs again but still no difference. Thought bugger it we will head out slowly as we were just going in the sound for snapper. Less than 5 minutes into it the engine came good and hasn’t missed a beat since

 

my question is I didn’t think the coil pack would have an intermittent fault, it’s either working or not? Correct me if I’m wrong. I’ve re checked all wiring and terminals again today and all is fine and runs fine on the muffs.

anyone have any ideas or had similar issues?

 

 

____________________________________________________________________________

I go boating not fishing


Alpha's picture

Posts: 193

Date Joined: 13/02/17

Test

Sun, 2018-09-16 09:58

 You can test the coil packs if you have a volt metre. Look it up on YouTube. Check the earth wire as well from the coil pack. I had similar issue on a 2 stroke Yamaha, gut feeling was saying electrical since all I did was change spark plugs, couldn't find fault with spark after testing 3 or 4 times. Must be fuel, pulled carburettors off found air oriface blocked, gave all the carburettors a really good clean and fixed issue. It's a long shot but if you haven't cleaned your carbs might be worth a shot. Once again look it up on YouTube it's easy. 

 

Piggy's picture

Posts: 534

Date Joined: 24/08/12

Thanks mate

Sun, 2018-09-16 10:35

 cheers for the feedback mate!

____________________________________________________________________________

I go boating not fishing

Brock O's picture

Posts: 3160

Date Joined: 11/01/08

Been through the exact same

Sun, 2018-09-16 10:44

Been through the exact same with mine...95 115hp, always carry a spare now as Chivers stock them...$60 odd from memory.

Dosn't hurt to pull them and clean the mating earth surface on the engine either, but as Alpha stated above...as ive done exactly the same...pulled carbies down to find small black piece in a fuel passage....turn out to be a piece of the VRO diaphragm breaking down which explaind a lot of other intermittent engine problems also.

Swapped over to a new fuel pump were i premix....100% improvment on performance and running.

Piggy's picture

Posts: 534

Date Joined: 24/08/12

Thanks

Sun, 2018-09-16 15:14

  cheers mate will look at that! 

I’ve already gotten rid of the VRO and premix myself! Will look at cleaning the carbies

 

so yours had a coil that was knackered?

____________________________________________________________________________

I go boating not fishing

Brock O's picture

Posts: 3160

Date Joined: 11/01/08

yeah had more than a few

Sun, 2018-09-16 16:49

yeah had more than a few tussels with then....had them drop out and come back on as you discribe.

Piggy's picture

Posts: 534

Date Joined: 24/08/12

awesome

Mon, 2018-09-17 14:34

Awesome mate thanks for that!!

____________________________________________________________________________

I go boating not fishing