THIS ALSO WORKS GREAT AS A STOCK 50 OR 70 REPLACEMENT !! * BUT SEE MODEL FITMENT BELOW IT WILL HELP IF YOU DRILL THE ORFICE BETWEEN THE TRANNY AND CYLINDER BASE TO JUST UNDER 2MM DIAMETER. THIS WORKS ON ALL ENGINES WITH CDI AND MOST ALL ENGINES FROM 1982 AND NEWER. (SORRY NOT THE ATC OR TRX 70'S THOU) IT HELPS TO DRILL THE ORFICE TO JUST UNDER 1.6MM SEE BELOW S1072 @ click on picture to SEE WHERE TO DRILL ORFICE OUT @ **SPINDLE OIL PUMP DRIVE 14675-178-000 1/21M (81L)THIS IS AN OEM OIL DRIVE SPINDLE. FITS: CRF50 2000 TO 2009 XR50 ALL CRF70 2003 TO 2009 XR70 1997 TO 2002 Z50R 1984 TO 1999 81L @ *BUSHING OIL PUMP SHAFT CRF50 CRF70 TRX90 15384-178-000 1/21A (251A)PIVOT, OIL PUMP FITS: CRF50 2000 TO 2009 XR50 ALL CRF70 2003 TO 2009 XR70 1997 TO 2002 Z50R 1984 TO 1999 251A