Carburetor problems? help and tech tips

I run 100LL Avgas. It works well for non modified motors and is about $4 a gallon. I've heard all the blah blah about Avgas but I ran it in a stock 05 CR250 for 4 years with absolutely no problems. I run it in my mostly stock Yamaha YZ465 vintage racer and that bike has 1 win and 1 second at Day in The Dirt in the expert class. I have no fear of avgas. Before that i drained everything before I loaded up. What a PITA.
It seems no matter what I do in my trailer, I need a carb about every 2 years from pump gas.