TOPIC:

yes i understand what you're saying.but there's a couple of points.

1. it is alleged and only a rumour so far, that here in oz,  a big batch of ngk's have entered our shoresfrom china....and they're supposed to be copies.not that my set were in one of those batches, i cant tell as
they look quite genuine to me..........but it's a thought.2. the ngk plugs that i have changed were brand new, with only about 20 minutes running time on them....3. this very same thing happened to me, earlier this yearwith my guzzi, which is a fully restored 1973 bike complete with a new engine,
upon introducing the bosch plugs on it, i have had no issues....yet.4. i spoke with my mechanic who did the $2000 job on thebike and told him what had happened and that i had replaced the ngk for the denso's.
he promptly saidto me, that he had another bike, a yamaha that had the exact same issues and
found it in the end that it was the plugs he had put in,
but never thoughtanything of it and continued to replace those .....they were indeed ngk's.i always had my suspicion on the plugs, after the episode with my guzzi,but i didn't discount the coils either.for sure, i never at any point thought it would have beenthe carbs.i guess time and a couple of long rides will tell.i will do that and i will know .

Bad NGK's ! Off -shore copies ? Hard to believe but with everything else being made overseas to dupe us, I guess it's plausible and your switching out of plugs prove something for sure !
I've always used NGK's without issues but did have similar problems originally with "Champion" - crap, although not as extreme as your concerns..
Ironic and frustrating that what seems so obvious in the end was and typically would be the last thing most would start with. In your case, It wouldn't have been my first thought, either.
Really glad to hear that you've got this sorted out !

Had exactly same issue with my R1 a few weeks back. Was riding perfect and then just dropped a cylinder. Tried coils carbs etc as ND plugs looked new and no fouled. But on putting in new plug in spot on and has been since. Moral of the story check the easy things first lol

the same here scotch.....twenty or so years ago the thing in plugs was champion. i was using them also....then the switch came to ngk's because we found champion were no longer good enough .....seems like history repeating itself.

the one thing i had in my favour was that i had time....i had already put on order a set of 6 densos and waiting for them to arrive, at the same time looking at all possibilities, didn't cost me..................but i was worried.

over  here in sunny Scotland there was a story going round about fake Chinese made NGK plugs being sold on the internet. I've been a bit suspicious of them ever since.

All fake plug issues aside;  I can honestly say, in all my years of riding - at least since two stroke days - I can't recall ever 'fouling' a set of plugs.  Not sure what I'm doing right.  The plugs in my 82 900F are at least 17 years old and the set before that were original.