Differences: There are no visual clues to tell a 125SX from a
150SX. Only the piston, rings, crank and jetting are different.
Here’s what we ran in our 38mm PWK (stock settings are in parentheses): Mainjet: 185 (182) Pilot: 40 Needle: NOZI Clip: Second clip from top Air screw: 1-1/2 turns out Notes: In cool conditions, we would consider a 190 mainjet and a 42 pilot. Q: WHAT ARE MXA’S RECOMMENDED 125SX/150SX FORK SETTINGS? A: The KTM 150SX and 125SX share the same components and setup. Here’s what we ran in our 125SX and 150SX (stock settings are in parentheses): Spring rate: 0.42 kg/mm Compression: 6 clicks out ( 12 clicks out) Rebound: 10 clicks out ( 12 clicks out) Oil height: 360cc Fork-leg height: 5mm up Notes: Bigger and faster riders should go to 0.44 or heavier springs. Smaller riders can easily take 10cc out of each fork leg to soften up the midstroke. Q: WHAT ARE MXA’S RECOMMENDED 125SX/150SX SHOCK SETTINGS? A: Here is what we ran (stock settings are in parentheses): Spring rate: 4. 8 kg/mm Hi-compression: 2 turns out Lo-compression: 15 clicks out Rebound: 15 clicks out Race sag: 100mm Notes: Given that the 125SX and 150SX have the same suspension system as the 250SXF, 350SXF and
Burst: There were steep step-ups right out of corners that
the 125SX couldn’t clear, but
the 150SX sailed over with
ease. The power was more
focused on the 150SX.