I just took mine apart and cleaned out the mud-wasp nests with hot water. Created a new outer gasket with an exacto knife (out of a plastic ziploc bag. Re-assembled and "tuned" with the adjusting bolt, and HONK, good as new. Whole procedure, both sides in under an hour. One of mine only hummed, the other only clicked. Both now operate like new. Good luck. If you'd like, you can send me part of the $40 you just saved! Steve Peck #3302