Back midway through the
BX23/
BX2230 production run the engines were changed from the D905 to the D902. I believe the change in the B2230 was more limited.
As was pointed out it was due to the new emissions requirements and Kubota met them before it was required. I'm going to guess that they decided to change to the compliant engine as it was ready and GTG at that time.
Along w/the engine change the hp was upped an additional hp to 23 from 22. So some of the 30 series BX's have 22hp and others have 23hp.
If you look at the listings on Kubota's web site it lists the
BX23 as 23hp. My
BX23 has the D905 and all the literature that came w/it indicates 22hp.
The D902's were installed in the 50 series as well as in the new 60 series large BX's.
So in conclusion, yes, the D902 engine thats in your
BX25 was also OEM'ed in the later model
BX23/
BX2230's.
I'd say the label on your engine is accurate whereas the literature in the manual can be suspect

Dave