From Honda Trail Bike Wiki
The standard 15 tooth front sprocket (296)can be changed for a 14 one, dispite the fact no one makes one! Have an engineering firm machine the raised section fron the outside of a 297 sprocket, and fit it with 2 circlips. This may sound insecure, but in 4000 miles and lots of off road there haven't been problems (yet!).
Further research and time has revealed that www.intobikes.co.uk sell a honda 296 pattern 14 tooth sprocket, and a 49 tooth rear. (Cheaper than above option.)
Also try WWW.WEMOTO.COM