I have to replace my plugs about every 800-1000 miles as they just don't last in my X engine and start running worse and worse at lower RPMS. New plugs, problem gone. It's the same thing as any other HP engine, plugs are a expendable item.

I have never been a fan of NGK, kind of like Champion brand in a car engine. I also don't much buy into the 'bling bling' plugs at $15 bucks a piece and think most are marketing and not technology. Are there some really good parts out there that you have had great luck with?

*flame suit on* NGK's suck! *flame suit off*

The above is only my openion and like we all know... they all stink.

With that out of the way... I like Champion plugs, but in my experiance, they tend to require one step hotter than reccomended.
Autolite seemed to be a decent milage plug in my Seca, but they aren't worth jack in my Vmax.
All of these splitfires and other silly "tuner" gimmick things are just paperweights. I believe you'd be better off "indexing" standard plugs (at least that way, you would have more time to drink beer while wrenching).

My rant is over, but...
If you're fouling plugs within eight hundred miles, are you sure that the bike is carburated correctly? That just seems way too short to me.
Maybe too much resistance in the wires and caps? Weak coils?
Just guessing here! (pass me a beer, please)

Yup, I think we are on the same page here. They don't foul, actually they read good at changing time, but they just won't fire right. I beat my head against the wall the first time I was trying to diagnose this becase they DID read good. Tried a bunch of different stuff to no avail, then changed the plugs out of frustration. Purred like a kitty.

I'm thinking yeah, maybe the coils or wires are weak but the plugs have to had gone away if a new set fixes the problem. I could install a set of hot coils and wires that would light the miled-out plugs and the running problem would go away but that would be masking the real problem.

Autolites are my first choice but don't seem to help in this situation. Bosch Platinums actually do seem to have an advantage in FI high comp car engines. They seem to foul easily in carberated car engines because they don't like rich mixtures. I haven't tried them in this so maybe I'll see if they have an application that will be right in this engine?

Hi Whisperer,

As you suggest, your coils sound like the real problem and not sparkplugs. Plugs are plugs, and they should all work beyond 1000 miles. Your problem shows up around 1000 miles in, when your plugs can't be considered "new" anymore and it can take a little more juice to fire them. If your coils are weak(er), they won't be up to the task. Have heard great reports from folks who have replaced their coils. I'd do it myself, but promised the wife the Seca was going to get more riding than fixing this summer!

GG