1977-2000 Suzuki DT5/6/8 Outboards Service Manual, Page 56Get this manual
fUEL SYSrEM TROLLING SPEED ADJUSTMENT Here's the procedure of adjusting the carburetor for making the engine idle at proper speed: (1) Start up the engine, and thoroughly warm it running for to 10 minutes in no-Ioad condition(2) Run in air screw all the way (to fully closed position) and back it off graduallyThe engine will pick up speed correspondingly but soon the speed will cease to riseSet air screw shortly before this point in engine speed is reached(3) Shift clutch into FORWARD position(4) Run throttle stop screw, moving it inward and outward to find the position at which the specified Trolling speed is obtainedSet the screw in that positionAir screw .setting