1 - 18 SPECIAL TOOLS GEN INFO Tool No. Tool name/How to use Illustration 90890-04134 YM-04134 Sheave spring compressor This tool is needed when removing or installing the secondary sheave spring. 90890-04135 YM-04135 Sheave fixed block Sheave fixed bracket This tool is needed when removing or installing the secondary sheave spring. 90890-06754 YM-34487 Ignition checker Opama pet-4000 spark checker This instrument is necessary for checking the ignition system components. 90890-06760 YU-39951-B Digital tachometer This tool is needed for checking engine rpm. 90890-85505 Yamaha bond No. 1215 (Three bond No.1215®) This bond is used on crankcase mating surfaces, etc.