"Frankly, I don't think an idle bar plug will help at all."

Trust me on this one....I had it proven to me over 25
years ago....blocking the fuel from the fire with a
barrior....will not promote a better idle. They should
call them "non-idling barred plugs". They're junk.

You especially won't like them when the idle bar breaks
off, and destroys your motor....which does happen.

You might give one of these plugs a try, the Fox Miracle
plug. They work great in two-strokes for two reasons.
First they have an extended tip design that does not allow
raw fuel to collect inside the plug....and they are a hotter
plug....which will help with some rich conditions that
occur with inverted engines.

Dave.