hey guys i have two saito 4 stroke 100fa engines and with one i'm haveing trouble with the muffler coming loose and just dangling, i've tried lock tight thats heat resistent and everything else but to no avail. on my last flight it didn't come loose for a change it just broke clean of right where the manifold goes into the muffler. so i'm wondering if you guys would have any ideas. i was thinking its vibration from the prop which i've tryed changing too but stil the same problem. the second engine seems to run fine but the valve covers get really hot and the covers on the first engine stay cool. the second engine when you turn the prop by hand has zero compression but seems to run fine and its only a month old. the engine with the muffler problems is a year old and has great compression when turning the prop by hand. so do you guys have any ideas on what the muffler issue could be on the first engine and if the lack of compression in the second engine is something to worry about.