Well the bike of my friend still on the same.....first just seems to be rich.....check compression, change carbs to PJ 34 methanol, changed CDI, Wiring, Spark Plugs, took off the stator and checked nothing wrong......right cylinder was dead, he took it up and nothing wrong, good piston, good rings, any trouble, after it was assembled again......now the left cylinder is the one that is going dead...what do you thinks guys could be the trouble??...