#48-5012 - Mixture screw Kit - Mixture screw Washer, O-Ring & Blind Plug

Mixture screw Kit - Mixture screw Washer, O-Ring & Blind Plug - Fits: 1980-84 XS650G/H/SH/SJ/SK/SL Stock Mikuni BS34 CV Carbs. Plug covers vertical re- cessed idle mixture screw & keeps out contaminants. O-Ring fits under metal Washer at bottom of mixture screw hole and the engine will not idle properly if it is not present - (O-ring is often disintegrated). These parts are not shown in service & parts listings as Yamaha did not want "emmisions" related parts accessed, however adjustments were often necessary to get New bikes to run properly. Suggested setting position of the normally hidden mixture screw is 2 1/2 to 3 turns out from bottom.