Polaris Ignition Update Kit | 1996-1998 SL 900 | 1996-1998 SLTX | when installing a replacement Polaris domestic CDI it is extremely important to verify correct flywheel timing Refer to a Polaris service manual for your specific models timing and time accordingly after the new CDI is installed. *Failure to follow this recommendation can result in piston deterioration and possible engine failure.