I'm looking for a pair for my 2004 749R, just wondering what are the best options? I normally use the stock champions as they give a lot less problems with the plug socket than NGK in my experience. What are people using?
Had mine changed last year when the belts were done. It had Champion Surface Discharge plugs before and these were replaced with NGK's. It ticks over much more reliably now, though still far from perfect and runs very well, if that's any help.
I'm using NGK Iridium. Iridium have a bigger plug gap as standard, which produces a fatter spark. The fatter spark, in theory, should give a steadier idle and better throttle response. Subjectively, I'd say that's true. However, NGK plugs have the hexagon, that the plug spanner fits on, lower down the plug body than Champions do, do plug spanners are an issue, as the well that the plug sits inside is tapered. I found that filing the oem plug spanner cured that problem though.
Just don't gap Iridium plugs and there should be non issues. They are preset and should not be changed. They are also less prone to fouling I believe.
Surface discharge spark plugs are mostly relevant when there is a risk of the piston hitting the electrode and yes, they are notorious for fouling at low engine temperatures especially at tickover. Fine on a track bike but more problems than any gain on a road bike IMO. Andy
Maybe I'm just unlucky, I was warned and found the plugs don't like over fuelling when cold and are a pig until the bike warms up. Although I have yet to try, I was aslo advised that they don't take kindly to being cleaned. I hasten to add that my experience is of a "cold" plug in the 748RS. Andy
