RE: clucth problem
Sounds like the clutch has started to unscrew from the crankshaft and is pushing the fan up into the cooling shroud. Be sure to use something to keep the crankshaft from turning when you screw it back on tight with locktite. e.g. remove the carb and stick something softer then aluminum (e.g. an old toothbrush handle) down the carb opening and jamming the opening of the crankshaft to keep it from turning.
Then be sure to locktite the prop nut to secure the fan.
When installed properly, your clutch will last a long time - I have well over 300 flight on one. IMHO, it has the most durable clutch system of any 30/50 size heli I have ever owned.