175 standard 2010 Optimax 1B789623. The engine idles and runs well except when it's in gear at low idle. Then it seems to miss and sometimes stall. It has done this for a couple years and I have changed plugs many times to no avail. In the plenum, when you look in the air intake, there's always a small pool of what looks like oil. Years ago, the serpentine belt rubbed when the air compressor bolts got loose and I'm sure that it sucked in a lot of belt "dust". Can't remember, but that might be when the problem started. Knowing that the stainless reeds can break, I'm wondering if that might be the problem or the belt dust could have caused a reed to hang open? Is it difficult to disassemble the reeds for inspection? If I went to carbon reeds, would I need to lap or do anything other than install and check gaps? I read where the stainless reeds have a neoprene surface that they seat against. What would be your recommendation?