090 ignition questions

I bought an 090 (says made in west Germany), had it checked out- P&C look good, just had an oem carb put on, and it will start run and die. I have it at a stihl trained tech and he wants to tap out. He said that he has tried to get it running properly and it starts, runs, dies, and apparently it...

I have been rebuilding my 090AV. it took months to get new check rings for my crank, so I can't remember a sealing ring #0000 992 5820 underneath the ignition unit. is this part a metal Washer, or is it something a previous owner could have lost? I put parts in bags when I disassemble and...