EXHAUST
MINI FACTORY 4.1™
EXHAUST SYSTEMS
  • Factory 4.1 muffler available in natural titanium
  • The lightest full systems available
  • Superior power and performance – horsepower improved throughout the rpm range
  • Factory Forward Engineering centralizes mass, improves handling
  • Made from premium quality American materials
  • Customize with performance tuning inserts and spark arrestor module
  • Meet AMA sound requirements on most models; inserts available for others
  • SUG.
    SUG.
    FITS MODEL
    DESCRIPTION
    P ART  #
    RETAIL
    FITS MODEL
    DESCRIPTION
    P ART  #
    RETAIL
    HONDA
    SUZUKI
    XR50 00-03,
    DR-Z110 03-05 Mini Factory 4.1 system w/ stainless steel header 1820-0499 $299.99
    CRF50F 04-16 Mini Factory 4.1 system w/ stainless steel header 1820-1323 $319.99
    YAMAHA
    KAWASAKI
    (all)
    Mini Factory 4.1 system w/ stainless steel header 1820-0502
    299.99
    KLX110/L 02-16 Mini Factory 4.1 system w/ stainless steel header 1820-0499
    299.99
    FACTORY 4.1™
    SLIP-ON MUFFLERS
  • Factory 4.1 muffler available in natural titanium or blue anodized titanium with titanium end caps
  • The lightest mufflers available
  • Superior power and performance – horsepower improved throughout the rpm range
  • Feature exclusive proprietary Chamber Core technology
  • Factory Forward Engineering centralizes mass, improves handling
  • Made from premium quality American materials
  • Customize with performance tuning inserts and spark arrestor module
  • Meet AMA sound requirements on most models; inserts available for others
  • SUG.
    SUG.
    FITS MODEL
    DESCRIPTION
    P ART  #
    RETAIL
    FITS MODEL
    DESCRIPTION
    P ART  #
    RETAIL
    HONDA
    KTM
    CRF150R 07-16 Anodized slip-on muffler w/ stainless steel
    250 SXF 05-08
    Slip-on muffler w/ titanium mid-pipe
    1821-0318 $399.99
    mid-pipe
    1821-0545 $399.99
    690 SMC/
    Anodized titanium slip-on muffler
    1821-0547
    449.99
    Enduro 08-13 Slip-on muffler
    1821-0859
    399.99
    CRF250R 04-05 Slip-on muffler w/ stainless steel mid-pipe
    1821-0249
    424.99
    SUZUKI
    CRF250X
    RM-Z250 04-06 Slip-on muffler w/ stainless steel mid-pipe
    1821-0287
    424.99
    04-09/12-17
    Slip-on muffler w/ stainless steel mid-pipe
    1821-0249
    424.99
    RMZ450 08-10
    Slip-on muffler w/ stainless steel mid-pipe
    1821-1146
    424.99
    1821-0282
    424.99
    YAMAHA
    WR250F 07-14
    Anodized slip-on muffler w/ stainless steel
    TC250 10-11/
    mid-pipe
    1821-0584
    424.99
    TXC250 10-12 Slip-on muffler w/ stainless steel mid-pipe
    1821-1585
    424.99
    YZ250F 06-09
    Anodized slip-on muffler w/ stainless steel
    1821-1581
    424.99
    mid-pipe
    1821-0584
    424.99
    KAWASAKI
    WR450F 07-11
    Anodized slip-on muffler w/ stainless steel
    KX250F 04-08
    Slip-on muffler w/ stainless steel mid-pipe
    1821-0287
    424.99
    mid-pipe
    1821-0584
    424.99
    KX450F 06-08
    Slip-on muffler w/ stainless steel mid-pipe
    1821-0379
    424.99
    YZ450F 06-09
    Anodized slip-on muffler w/ stainless steel
    KX450F 16-17
    Slip-on muffler w/ titanium mid-pipe
    1821-1762
    499.99
    mid-pipe
    1821-0584
    424.99
    DISCLAIMER: NOT LEGAL FOR SALE OR USE IN CALIFORNIA ON ANY POLLUTION CONTROLLED MOTOR VEHICLES.
    SEE PAGE 4 FOR IMPORTANT EMISSION DEFINITIONS AND REGULATORY COMPLIANCE AND WARRANTY INFORMATION.
    2018 PARTS UNLIMITED OFFROAD