Topic: wrong type of plugs? i hope so...

[sounddoc]

hi all,

on the way to work today on my '75 750F, i dropped to 3 cylinders....then 2 briefly....then none. All I have done prior was change the plugs (stupidly) to the stock NGK D8EAs. stupidly, as I have aftermarket coils in there (not sure the brand, I'll have to pull the tank off, but i'm at work) and a Dyna ignition. the plugs that came out were champion 8809s. when i took a look at the NGKs after the engine died they are the most perfect dusty grey colour. could it still be the wrong type of plugs though? i rode about 14 miles just fine before it died, and again at lunch for about 2 miles before meltdown. the #4 carb is out of sync and has a leaky valve seal, but other than that and the plug change, i can't think of anything else that's causing this. any ideas? in the meantime i'll try to get my hands on some champion 8809s. thanks!

-Pete

[eldar]

The NGKs are better than champions generally. A plug fault might happen with one plug but not all. I would look at a fuel issue or spark problem fisrt before bothering with plugs. Electronic igns DO fail and coils do fail and fuel may be getting blocked if your filter is plugging or the screen in the petcock.  When the cylinders started to die, which ones went first? This could give you a clue if it may be ign or coil related.