how is the low mixture set on what i think is a sf 120. have experience on fz .63 and .91.
this engine however has short screw in throttle barrel, Plug? does't seem to be anything inside but darkness
thanks for your help
mike

They had a fixed idle with an airbleed hole in one blade of the throttle barrel. If the engine is too rich at idle, this hole will need to be enlarged by drilling. We usually take them up to 1/8", but I would go a little at a time to avoid a problem. The existing hole is a little bigger than 1/16".