When i bring my V1 rappy 30 up to hovering speed i get this noise like crunching or rattling like something is wrong.lol but only at a certain rpm which i dont know which rpm its at anyways at anytime. Also my muffler keeps coming loose even after i red loctited the ******* with a nyloc nut on it? I have a helimax tuned pipe with header for .30 sized engines should i put that on? I have a O.S. 32 SXH motor and i usually run powermaster 15% in it. But recently switched to coolpower 30% and it doesn't seem like it really likes that. Or i just dont how to exactly tune in my motor after repeated readings of directions and other info sites like raptortechnique.com Any advice or tricks, tips, etc. would be oh so deeply appreciated

pe@ce [&o]