Hitachi help

[Rotary Evolution]

yes, normally the idle mixture screw is set at about 2.5 turns out on a stock carb, it's possible someone mixed up nikki main jets for the primaries or used the carb on a 12a and rejetted it. at this point in time it's difficult to know what has happened to the carb over the years.

i forget offhand the stock main jet sizes but i want to say 60 primaries and 90 secondaries but that could be nikki jets. if i get a chance i will see if i have the numbers written down on my carb sheets.

the idle screw isn't critical, you can also use the butterfly cam stop to set the idle as well if it is giving you difficulty. the cam stop is located under the throttle cable on the carb cast iron base.