I purchased an 89 Warrior and it was running okay when I bought seemed like it just need the carb cleaned and adjusted. I changed the oil, spark plug, oil filter and checked the valves. The old carb busted when I dropped it. I did the Z400 carb mod and now its misfiring and not staying running unless choke it on and smoking out of the muffler. It has a 150 jet, 60 jet and 22.5 pilot jet. It has an aftermarket exhaust and Uni air fliter.