For me. I've never had a spark plug oiling issue. And I always start inverted. Engine mounted inverted in a comp arf valiant. Starts perfect after fueling and priming. However any change to my set procedure of fueling and priming leads to a fussy engine. But that's only on the first start of the day. After that each subsequent start is on the mark. My last little event described I this found was due to a worn/stretched diaphragm in the regulator. Easy fix. All is well now.