Start with the simple things first.
Spark plugs - you have put new ones in first - right?
Are those two cylinders fed from the same fuel line? i.e - can we rule OUT a lack of fuel in those two cyclinders BEFORE we start down the road of testing the electrics?
What GIVES the two power packs their high voltage - to set off a spark in the spark plugs?
Isn't it a fluctuation LOW VOLTAGE (12V) current, thru a coil of some sort (isn't that all the myserious "power packs" REALLY are? - Glorified coils!).
Do you have an obvious "short" anywhere in the 12V low voltage side feeding those two power packs?
Have you tried turning off ALL the lights at night and then cranking her over to look for leaking spark?
Have you tested the NEW spark plugs OUT of the spark plug hole by holding them (with insulated handles pliers) with plug lead connected - with body of plug against an earth part of the engine block and cranking it over and looking for spark?
Eliminate the simple stuff - the spark plug leads are they cracked and leaking high voltage across to some part of the engine that makes an easey earth? (Cowl catch etc?)
Like i said - it's too easy to throw $ at finding the problem.
Someone I Know bought a band new OB....and within the first 20 hours it just went stone motherless DEAD as the proverbial dodo.
It was under warranty and we had a big trip comming up at the end of the week - some promotional filming etc..for which we needed that boat.
Soo - in it went to the dealer, who started "swapping" new parts from an in stock engine to get us underway again.....
It didn't work - the engine was still dead and in the end they had put a whole new powerhead etc on it from a brand new engine in stock, and it still had the same problem...
So they swapped it all back to the original powerhead, still dead.
They gave up and went home - rang us the next day to say they were totally baffled / stumped / gazummped and bamboozeled...as to what was wrong and explained the lengths they had been too - to sort it out, but alas to no avail...
They were going to talk to the manufacturer about supplying a new replacement out of stock OB under warranty, to get us away on time for the promotional trip.
10 Mins later - they rang back - and it was "all fixed".
They said they gave it "one last crank" in frustration and it started and ran like a swiss watch.....(but it never did the night before, after a few days of solid working on it).
Anyway they switched it off, and then on again - restarted it maybe a dozen times and it never missed a beat. Then they rang us to give us the good news.
To this day - no one knows what was wrong with that OB...but it has never missed a beat since, still starts first time every time - one of the most reliable OB's I've known..
Sometimes ya just get that - something probably so simple - that NO One Spotted, that somehow just 'fixed itself' without explanation.
Strange things happen sometimes!
I even knew a Mechanic once, who when folks were "slow" paying (or werent going to pay) for repairs, who would "find" their vehicle at the supermarket or wherever (the hotel carpark where they drank), and he would just "pop the hood for about 30 seconds....and using a lead pencil...mark a line down the insulator of each spark plug and replace the leads, drop the bonnet and walk away.
The car would usually get "towed in" for repairs that day or the next...with some "major ailment"...diagnosed of course by 20 "experts..and he would just say - we it's going to cost you what you owe me already upfront before I'll look at it- then we'll take it from there.
Of course they would pay up (who wants to walk?) and he would have it "fixed" in about 10 seconds, bye wiping off the lead track he'd made down the outside of the insulator and putting the leads back on.
If they had half a clue or good vision he make the lead pencil track inside their disrributor cap where they couldn't spot it.
Theres a zillion ways to "stop / disable" a car without causing major damage....
Same with your OB - there could be something simple - are the two leads in question crossed? Have you been messing about and swapped em over so they fire at the wrong time?
Look for & eliminate the simple stuff first, Mechanics diagnosing and quoting always diagnose the worst case scenario to cover their butts, and if it turns out to be something simple a lot won't say so - they will do the work they have quoted on and supply the new parts anyway, purely because it keeps them in work and they likely get a markup on the parts as well.
Cheers!
2 cylinders not firing
