I have an alpha trainer and I'm having trouble with the engine. When I get it started it runs very rich. When I give it throttle it starts to spool up and lots of fuel comes out of the exhaust. I have taken off the needle stops and have adjusted to every extreme and fuel is still coming out of the exhaust soaking the ground. I took the tank out and checked the lines and cant find any air leaks. Any suggestions on what to check next?