Oil pressure & weather conditions

[marek4792]

Assuming your tune isn't the issue like Rawze says or an underlying performance/ cooling issue, your oil pump could have a weak/ broken regulating spring. I ran into that one on mine. Went from mid to high 30's down into the low 30's one day. Swapped when doing rods and mains and it returned to high 30's. Of course each engine is different. Most important if the proper gear lash can't be obtained, get another one until it does.