Generator: would stop when the engine got warm. Code 36: unexpected shutdown. Lowered oil level to add mark, no change. Became suspicious that there was a fuel issue, possibly vapor lock. Found an extra in-line fuel filter just before entering carb. It had melted and was out of its original shape. Also discovered that the fuel filter on fuel pump was very old, probably original. Changed fuel pump (very complicated and not easy to get out) and fuel filter, changed 1/4" fuel line from new pump to carb, added heat shielding to fuel line as well. Fuel line was adapted from 1/4" to 3/8" to tank filter using a 1/4" to 5/16" barb. Fuel hose clamps used where possible. The new pump's electrical pigtail was too short. Added an extension and wire protection due to vibration. Ran generator without unexpected shutdowns but not with a full electrical load. More testing needed.