sjs
11-15-2008, 07:28 AM
hi all, i recently reluctantly agreed to look at somebodys 12 month old jianshe mountain lion 400, the bike was running rough and popping back through the carb and sometimes blowing it completely off, i tested all the electrics as i thought it was simply a spark timing issue, i switched the cdi, stator, pick up coil, coil, sparkplug, regulator, rectifier, new gas, all with no luck, i fitted a new carb and inlet manifold with the same result, i checked the timing and found it was out by a tooth (retarded), the owner said the bike hasn't been messed with so i'm guessing it's been a tooth out from new, the timing chain was tight and all teeth were ok, when the timing is set correctly the bike just hydraulics and won't turn over, when the bike was running with a tooth out the header pipe would glow red within 30 seconds of starting and the plug looks very white, all tappets and timing have been set right but engine still hydraulics, checked for valves hitting piston and all was ok, finally decided to remove head, slight wear on cam lobes, slight piston wear, valves look ok, rocker arms ok, anybody any ideas, Steve:mad: