2008 Suzuki LT-A400/F, LT-F400/F ATV Service Manual, Page 186Get this manual
1G-19 Fuel System: 9) Remove the following parts Main jet (20) Needle jet holder (21) Needle jet (22) Slow jet (23) Starter jet (24) Pilot screw (25) NOTE Before removing the pilot screw (25), its setting must be determinedSlowly turn the pilot screw clockwise and count the number of turns until it is lightly seatedMake note of how many turns were madeWhen reassembling the pilot screw, you will want to set it to its original positionPilot Screw Removal (For Tampering Plug Type) Because harsh cleaning solvents can damage the O-ring seals in the pilot system, the pilot system components should be removed before cleaning1) Use 18 size drill bit (1) with drill-stop "A" to remove the pilot screw plug (2)2) Set the drill-stop "A" mm (0.16 mm) from the end of the bit to prevent drilling into the pilot screw (3)3) Carefully drill through the plug (2) "A" 2