Hey everyone, Just after some advice, have 03 xr6t, auto, 100000klms, and have found when I run at full throttle I lose out in the top end of the rev range, feels really flat over 4500-5000rpm, and when I back off it sounds like its runnin on 4 cylinders for about ten seconds. Have done the plugs 1 month ago 0.8 gap, thought that was the problem. If I change manually before 4500 it pulls hard and theres no problem at all. I am running at 10psi generic tune now, but it still happens on the stock tune, only other mod is centre muffler removed. From searching on here I thought probably valve springs? Any help much appreciated :banghead:
