My Muzzy full exhaust I bought used was from a pre-09 "he said " if I remember correctly. He also said it would fit on my 2009. Was he bs-ing me? the numbers on the back of the cone says MZ-0023.

 

Complete systems are interchangeable. This includes KLX300R systems on KLX250S's..

 

Wow thanks for the quick reply KLXter. I 'll be running lidless with the DJ144 recipe you recommended starting tomorrow.

 

If perhaps it's from a KLX300R would the jetting be different? Just trying to not have to jet twice.

 

it will work just fine

 

Full Muzzy system uses the DJ144 lidless setup - as will all full performance systems (header + slipon)...

Stock headers with performance slipons use the DJ140 lidless setup..This is regardless of whether you are running a stock KLX300R header or the stock 250 header.
If running a stock 300 system (header + muffler + performance end cap or no endcap), you also use the DJ140 lidless setup..