I have an older OS MAX .61 SF ringed engine & no instruction manual. The Carb is a bit different from those that I am used to. Need to confirm that the idle mixture screw is acually on the same side as the high speed needle. The screw I'm speaking of is a small flat-head, and looks like it is in the jaws of a mimi open-end wrench. (obviously it is not, just trying my best to describe it) Also, there is a rearward facing screw just behind the throttle lever, about 90 degrees from the idle stop adjustment. What does that do?

This engine was stored for about 15 years (give or take a few) and was still NIB. I ran 3 tanks through it for break in & it runs great. Just need to tweak the low-end setting & want to make sue I turn the right screw.

On this engine, the "normal" spot for an idle mixture screw appears to be occupied by a black phillips head that acctually holds the throttle arm on. I think.

One last (minor) question...while running (very rich setting), oil seeps from the muffler-to-engine mounting area. Should I put a gasket there? Would it hurt to?