I have a 18tm and when I start it up it seems fine for awile then when I gas it it will die. Even when it is warmed up (240*) it will die. There are air bubbles in the fuel line that don't go away. It is brand new fuel line so the only thing I think would be bad is the carb o-rings. What do you guys think?

If you have bubble in the fuel line, you have an air leak somewhere. There can be no question about that. It cannot be carburetor o-rings because they come after the fuel line, as far as fuel system routing is concerned. You'll have to investigate why you have bubbles in the fuel line first. Eliminate them and go from there.

First replace the O ring on the gas tank. Take the tank off, empty it of fuel. get a spray bottle and fill it with water and dish soap. spray all over the tank, cover one hole up with you thumb and take the other end and BLOW! IF you see bubbles anywhere, then work on them.

great.... Whell could you give me a idea on where to start?

i had the same problem with my jato. it turned out to be the pickup tube in the fuel tank was cracked. so like bax said start from the beginning and work your way back.

In any troubleshooting job, you start at one end of the system and work your way towards the other. Check everything carefully for cracks, holes, and splits.