Hello,
I have been working on this Troybilt tractor...had a guy bring in the tractor, he said it was blowing smoke terribly while running. I figured it was the Nikki carburetor leaking into the crankcase and when he brought it in, the crankcase was full of gas. Drained the oil/gas, filled with fresh gas after taking the Nikki carb off and replacing the O-ring. Thought I had it whipped...but the engine wouldn't run, it will start if starter fluid is introduced but once it's burned off, it won't run. I figured I screwed up the o-ring/carb so I ordered a new carb, installed it...it will only run at full choke, once you release choke it dies. I imagine if I put on the old carb, it would do the same. I took off the gas line, it's flowing gas very well, it's not plugged at all. Is it possible the motor is fubared due to running it with the oil/gas mix? I cannot figure this thing out!