I recently sold a few conversions with the newest version of the Chinese ignition everyone is now using...
The cap is made to fit the 5/8 hex 14mm Champion RDJ7Y spark plug...
The plug has a taper seat instead of a gasket...
The plug WILL work in an engine made for the RCJ7Y spark plug that uses a gasket..
I cut an old cylinder in half and screwed the spark plugs in to check the distance to the end of the plug from the inside of the combustion chamber...The distance is almost exactly the same with either plug, maybe a few thousandths difference...
Either will work...There will be a version with a Bosch cap clone available so those who think a taper seat plug will not work in their engine...
My conversions with the ignition circuit inside the mount will still use the C&H circuit with syncro spark, engines with a separate ignition box will be Chinese from C&H..
A word of warning, a taper seat spark plug has been known to split an SPE 26cc cylinder when screwed in too tightly...Must be some really good aluminum..