RE: Pre-igniting Leo 46?
Mike,
The OS A3 is probably the hottest plug in current production.
Hot plugs go with little engines, low nitro and low compression...
In their larger engines, OS [link=http://www.os-engines.co.jp/english/line_up/plug/pluindex.htm]recommends[/link] this plug only for break-in...
The only larger engines that run very well on this hot plug (without resorting to too rich a mixture setting), are Evolution engines, as detailed by Barry Williams (blw) in other threads.