Originally Posted by
Muggydude
(About) How many turns out should the low speed and high speed be for my os 21vzb during a heat cycle break in?
Depends on what it takes to still be rich and actually warm the motor up. Throw some insulation around the heat sink, start at .5mm out like the manual says, set the idle at the factory position, then lean it out enough to get it started and keeping heat. Note that a race tune on the LSN is just about flush, so if you get to flush, you've probably gone too far. I had to lean mine out a bit to get it to run and spit fuel. Just start where the manual says and lean it until you can keep it going and building heat but still rich. It also depends on what pipe you have and the fuel you're using.