For $12 put a bottle of Lucas Oil Stabilizer in and you will be amazed at how quite that motor will be. It's available everywhere and one of the most used additives, even by techs who get tired of hearing from customers with complaints about the "engine noise" of the ticking valve train. It's an open mounted motor and typical noises become "annoying" to some.

 

If JohnnyC's suggestion doesn't help, I'd be thinking of worn out cam bushing (in the nose cone).

 

turn the radio up and enjoy......bahhahahaa


that's the conclusion I have came up with on my andrews

 

Already getting cash together for a boom kit tourglider great minds think alike I guess