Originally Posted by Uncle Fester
But the question still is the old method of reading plugs was really for carb's.
With EFI its not the same... is it?
EFI vs carb: It's the same. You're looking at an end result, not the fuel delivery.
The plugs look fine, but as stated, possibly some preignition.
EFI plugs are generally lighter then carbed plugs because EFI is more efficient, uses less fuel during warm ups, which in turn, leaves less residue and less carbon, due to less fuel used, but more importantly, a more consitant delivery.
EFI isn't effected by gravity, bike lean angle, ambient temps (as much), or things like worn needles, loose jets, float settings, choke issues, enrichener issues or bowl vents.
Of course, that because EFI is programmed to run at specific, consistent a/f ratios, and not all over the scale, like a carbed motor does. EFI is also set to run at 14.7:1 by most if not all MFGers, so a whiter plugs will be seen on stock bikes, or ones with a stock ECU program.
Better, richer settings are applied to EFI, to obtain more power, cooler running temps, richer mixtures, resulting in darker colored ceramic on plugs.
The MFGer could care less what the plug looks like. They go by EPA rules.
Most Asian bikes used to run a 16 or 32 bit ECU, which was slightly richer then most US bikes. It was nice, because mods effected them less. They were also water cooled bikes, so heat was controlled better, unlike our air cooled bikes.......