http://www.theblowershop.com/faqBlown 23 T said:
You should run a High Quality 80w/90 gear oil with a GL-5 rating. Synthetic oil or Synthetic blends are OK to use
http://www.theblowershop.com/faqBlown 23 T said:I have a new 6/71 blower i just put on i noticed that the oil in the little window is low what kind of oil do i use ????? 90 weight