14x25.4x6mm rear,7x19x6mm front.I put the tko ceramics in mine this week and man what a difference.I put the front in also.I had boca ceramic hybrid bearings in it and noticed no increase in performance.Changed those out after 1 gallon cause rear bearing went south.Also I am really starting to like the performance of this ninja.I was able to get a real nice tune out of it after putting those tko ceramics in it and it is keeping up with 700 dollar motors now.I might just get another one because of the price difference and have it modded.