Choke, cough, sputter!
 

My 98 SH will run great for about a minute but then starves for fuel...until I give it a lot of throttle. Then it will run OK for a bit again. Hole in the diaphragm? What is the easiest way of draining the tank to take off the fueling valve?

Close the valve before taking the tank off, and then hang tank off the edge of a chair, and connect a short hose into a fuel can, open the valve and let it drain. Due to the location of the valve, you may have to slosh it a little to get the last of the fuel. Even then there will be leftover, just keep the tank upside down while you have the valve removed.

Ive raised the tank, put it on a stack of tired. Than used some fuell ine and put one end in the tank and the other in a empty can, sucked the fuel line and there you go

JIGGLER! Quickest, easiest siphoning device I've ever found! Amazingly simple and fast. I got it at HD in the plumbing department. $10.