1999-01 Product Service Bulletin Engineering Services Models Affected: ST723, ST926, ST1030 Serial Numbers: Some 1997 & 1998 production units. Issue Reported: Field reports have indicated that these units may throw the transmission drive belt off from the engine or transmission pulley. This can occur when the transmission engagement lever is disengaged.
1. Adjust belt guides at the engine transmission pulley. Facing the engine pulley, locate the left hand guide in a down posi- tion and the right hand guide in an up position. With the engine off, clamp the transmission engagement lever down on the handle. Position the guides in the position described above.
2. Remove belt guides mounted to left hand side of frame under belt cover. Remove belt cover and locate two belt guides bolted to left side of frame near front motor mount. One guide is orange and the other is gray. Remove the bolts securing the guides and remove the two guides.
3. Reposition the grey belt guide. Take the grey belt guide removed in step two and install it in an inverted ( upside down )position in the hole located closest to the engine. This is one of the two holes used to hold the guides in place when removed in step two.
4. Adjust grey belt guide. With the transmission belt in the engaged position, lightly bend the guide away from the belt so that the bottom of the guide will be approximately 3/16 inch from the sur- face of the belt. Transmission Belt guide inverted.