Trouble shooting a Princess Propane 2273. Works alright in cool temperatures. Once outside temperature heats up, the electric ignite works, but will not hold the flame. Does propane go stale? This tank was filled about 5 years ago and has not been used in about 4 years. I really feel like it is not getting adequate propane to sustain it. Have tried the soapy treatment around the connections in stern locker for leaks. Once it is closed down it takes about 15 minutes to go to zero. This is on a 29.5 Hunter. Where should I be looking? Thanks, Joan