HI I am having some trouble with my thundertiger 25 when ever the engine is flicked over air is let into the fuel tubing and then after about three flicks the entire tube is empty of fuel any sugestions?

Do you have your pressure line on the carb and the feed line on the muffler??? That could do it.

no the lines are fed corectly this problem only developed lately

You can check the fuel lines in the tank for splits and holes. Do you have an electric starter? Spin it faster and see if fuel comes up the line. Or plug the exhaust port when you flip it a few times. Have you changed the location of your engine or feul tank. If your tank is to low in relation the the carburetor spray bar gravity might be your culpret. (spray bar is idealy center with the tank (you rarely get an ideal set up))

Are you flipping with the throttle at idle or wide open? Idle is the proper position for starting an engine.

I'll go with a crack or hole in the supply line. Possibly a clogged or kinked line. Don't forget to check the brass tubes in the tank, too.

Dr.1