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05+ TRX 400EX 400X Big Bore 87mm Complete Rebuilt Motor Engine Rebuild Parts Kit


Compatible Vehicles
Submodel Year Make Model
TRX400EX 2x4 2008 Honda Sportrax 400
TRX400EX 2x4 2007 Honda Sportrax 400
TRX400EX 2x4 2006 Honda Sportrax 400
TRX400EX 2x4 2005 Honda Sportrax 400
2x4 2014 Honda TRX400X
2x4 2013 Honda TRX400X
2x4 2012 Honda TRX400X
2x4 2009 Honda TRX400X


  • NEW 87mm after market cylinder
  • CP JE or Wiseco forged piston**
  • Hi temp piston rings
  • Wristpin
  • Circlips
  • Hotrods or Wiseco crankshaft with rod**
  • Crank bearings
  • Transmission bearings
  • Head stud kit
  • Complete gasket kit - head base intake exhaust case covers pump covers orings
  • Complete crankcase oil seal kit
  • Heavy duty timing chain conversion
  • Clutch kit

**DUE TO CONSTANT BACK ORDERS FROM MANUFACTURERS CAUSED BY COVID WE STOCK THE SAME 400EX PARTS FROM DIFFERENT COMPANIES SO THAT WHEN, NOT IF, ONE IS ON BACK ORDER WE HAVE AN ALTERNATE THAT IS THE SAME QUALITY TO SEND SO YOUR ORDER CAN GO OUT.  IF YOU ONLY WANT A CERTAIN BRAND PISTON OR CRANK JUST CONTACT US!  This is a bolt on kit that requires no machining of any kind.  Runs on pump or race gas.  All parts are new in the original packaging, and the original manufacturers' warranties apply*.

Please check your order thoroughly when receiving it.  If for any reason at all you are not 100% happy please contact us right away so we can help resolve the issue.  If you no longer want/need the parts you receive you are welcome to return it UNOPENED NEVER INSTALLED COMPLETE (NOTHING MISSING) AND BRAND NEW IN THE ORIGINAL PACKAGING for a FULL REFUND! *If we receive your order back incomplete, packaging ripped open and/or parts missing we will have to deduct our loss from your refund.

*We recommend that this kit be installed by a qualified mechanic with experience working on these types of motors.  Warranty does not include any failure that is a result of improper installation, improper tuning, improper break in, or misuse.  Piston comes with specific instructions for setting the ring gap.  If you do not follow these exactly your motor will fail.  For any warranty to be considered the part(s) in question must first be sent to us and possibly the manufacturer for inspection.  We can not warranty parts based on photos or phone calls alone.