THERE IS A CHANCE YOU WILL HAVE TO USE THE THROTTLE SLIDE CAP OFF YOUR OLD CARBURETOR. WE HAD TO FOR OUR 79 ATC110. THIS MAY REQUIRE YOU TO FIT A NEW THROTTLE CABLE ON YOUR TRX90 IN ORDER TO USE THIS CARBURETOR!! PLEASE MAKE SURE THAT A RIGHT HAND CHOKE AND PETCOCK LEVER WILL BE ACCESSIBLE IN YOUR FRAME!! YOU ARE BUYING: 1 new aftermarket carburetor Comes with fuel filters, Fuel lines, Fuel hose clamps. (THIS MAY REQUIRE YOU TO FIT A NEW THROTTLE CABLE ON YOU TRX90 IN ORDER TO USE THIS CARBURETOR!!) - MAIN JET IS: 78. - IDLE / PILOT JET: 32 PLEASE MEASURE YOUR OLD CARBURETOR COMPARE TO THAT BELOW: - MOUNTING BOLT HOLES ARE 48 mm CENTER TO CENTER. - AIR BOX SIDE FITS A 40 mm BOOT / TUBE. - HEAD SIDE OF CARBURETOR IS 22 mm INSIDE DIAMETER. YOU MAY HAVE TO CHECK RE-JET THIS FOR YOUR BIKE DUE TO CIRCUMSTANCES / MODIFICATIONS OUT OF OUR CONTROL, SUCH AS: - YOUR ALTITUDE / ELEVATION - EXHAUST PIPE - INTAKE SYSTEM - ENGINE HOP-UP / BIG BORE KITS - STROKER CRANKS - MODIFICATION WORK - HEAD WORK (PORT / MILLING / VALVE WORK / ETC...) WE HAVE INSTALLED ONE ON A 1979 ATC110 IT RUNS OUR MACHINE GREAT, BETTER THAN THE STOCK ONE DID. WE HAVE THIS IN HAND RIGHT NOW TODAY. WE SHIP VERY FAST. BUY HERE WITH CONFIDENCE. THE COIN PICTURED IS FOR SIZE REFERENCE ONLY, IT IS NOT FOR SALE AND IS NOT INCLUDED IN ANY PURCHASE EVER.