Stage 1: Single cam engine. Excellent top-end power increase. Works well with big-bore kits. Uses stock auto-decompression mechanism. Uses stock valve springs and rockers
2000-2002 KTM 520
2000-2002 KTM 520 EXC
2000-2002 KTM 520 SX
2000-2002 KTM 520MXC
2003-2007 KTM 525
2003-2007 KTM 525 EXC
2003-2007 KTM 525 MXC
2003-2007 KTM 525 SMR
2003-2007 KTM 525 SX
2003-2007 KTM 525 XC