RE: SYSSA 30CC GAS MADE IN USA
While a 100rpm reduction is likely all that, this is a new engine yet to be broken-in which is exhibiting teething pains. Thus my suggestion to drop 300rpm, this will create a baseline that the will hopefully exhibit good operating parameters. Once its established the engine will operate reliably without ”coughing” one can take another look at adjusting the needles.
FWIW: There is little to NO advantage to running a gasser overly rich IMO and in fact its detrimental to the engines long term life expectancy.
Michael Glavin