I have tried to research my problems through the various contributions in the discussion area, to the point at which my brain is now cottage cheese!!....... I know the answers are out there, somewhere....however, I figure it best to start afresh with my problems and current spec. on my 2001 WR 426....... When riding,at 1/4 throttle the revs are eratic, almost like a missfire, extra throttle and it clears! Bike is drinking fuel, 3 litres (1/2 gallon) more than a YZF 426 over the same distance. I am currently running stock jetting: MJ:#165 MAJ:#200 JN:#0BDQR-4 CA:1.5 PJ:#42 PAJ:#75 PS 7/8 With no air box cover and yzf426 pipe. Although I will probably need a quieter pipe for UK enduros (82 db?) Any quick fixes???