I'm in the same boat. When you say to run a 160 or 165 is that with or with out an air box lid?
I have a stock '85 ATC250R. Stock carb, stock piston. It has a DG pipe and I'm trying to jet for no air box lid. It had a 130 and I'm up to a 150 right now. The best I've got it to run was a 142 with the air box lid on. I don't have any jets between 150 and 180. Should I try buying a 160 or somewhere around there? I'm pretty good jetting 4-strokes but I can't really tell if I'm lean or rich.
2004 TRX450R, HRC equipped, Yosh full system. SOLD
2003 TRX400EX
1993 Harley Davidson FXSTC
1992 Mustang GT 331 Supercharged 6-speed
1985 Mustang GT
1985 ATC250R ESR
1985 ATC350X Restored
1984 XR500R
1982 XL500R
1977 F-150 4x4 4-speed 460
1976 TT500
1966 Fairlane