Rough idling/cutout when hot

[Falcon 269]

Smacks of float needle valve seat O-ring failure.  Not an issue when the motor is cool but as the engine warms, the rich misfire starts to affect the idle.  Also, it takes a while for the fuel level to rise above the norm as the leakage is probably not that severe at the moment.

http://www.yamahafz1oa.com/forum/showthr...ilure+mode