1986 xt600 dies at above 4000 rpm when warm
My XT has been giving me trouble lately. It starts and idles fine. While it is still cold I can run it up through the gears to 6500 RPM or so, with no trouble, but once it is warmed up, say after 5 or 10 miles, it will die above 4000 rpm(usually backfiring in the process, but after coasting a bit it will usually refire on its own). If I stay below this, it seems to work fine. I have cleaned all the passageways in the carbs, as well as the fuel strainers in the tank. The ignition coil secondary has a resistance of around 20k when cold. This is quite a bit higher than the published number of 3.5-5K. The plug looks good.