RE: ASP 21 GOING CRAZY trying to find the propnut size and thread count??? HELP
The [link=http://www.truturn.com/af_asp.htm]TruTurn Adapter Finder[/link] says the thread is 1/4"-28, for all ASP .20-.5x engines.
Either they are right, or they are wrong, but according to them it is not an M6x1.0 thread...