Hi i have a Os 18 TM installed in a lightning gt10 and i can't find the factory settings.i bought it used and the guy didn't tune it.

The initial "ball park" settings are in the manual. You can get one here:

http://www.osengines.com/manuals/index.html

hi

ok the high speed is 4 full turns out for a good len/rich run . the Metering Needle has 4 full turns out, Mixture Control Valve 2 full turns and half out. hope thats helps