make 2017 ktm 50 sx faster out the start gate

There are 3 screws on the clutch, winding them in will increase the revs before the clutch engages so the bike will take off harder. Winding them out will let the clutch pick up earlier meaning less revs to get the bike moving.

Clutch settings & Gearing are key to good performance for KTM 50's.
Is your rider fully tapped out down the longest straight ?
If not make the rear sprocket 1-2 teeth bigger this will help enormously.
Heavy duty springs & belleville washer will also help especially for the heavier riders.
It's a good idea to run a clutch cover with an adjustment plug make life a whole lot easier.
Too much spring pressure & you will loose performance because will effectively not engage till too late in the power curve, Too little & the clutch will engage too early dragging the motor down (bogging).
HOPE THIS HELPS ?

sTEVE
f1 mOTO

Adjust your engagement to hit higher in the rpms. The kiddo will have to ride it like he stole it though.