Jess....that's another old Wives tale....a K&B .61 which is loop scavenged cross
flow, with a baffled piston will run better and idle better with a K&B 1L plug,
rather than a Fox long idle bar plug. Of course now, this is only my finding, and
I've only been on this experiment since 1972, so I'm sure the next poster will
say his K&B's run better with the Fox plugs, and don't idle at all with the K&B plugs.

BTW....keep this under your hat....Cast iron (rings) and steel (cylinders) expand
at the same rate. Also, when cylinders are bored and honed in the manufacturing
process....they are indeed perfectly round. The rings are made as round as is
humanly possible, and the slight (negligable) imperfections (high spots) wear
quickly into the bore. This is how single ringed two stroke engines run quite well.

And remember this....an Engineer is a guy that says...."that won't work"....

....and a Mechanic is a guy that says...."O yeah, watch this".

FBD.