Yes, you should be able to do that.
Note that there are two recording modes-- the default mode that records the keyboard plus accompaniment, and the mode where you specify which track you want to record to.
There are six tracks that you can record to-- five melody tracks that record what you play on the keyboard using the Main Voice and (if enabled) the Dual Voice, and the sixth track that records the accompaniment.
To record what you play without an accompaniment, follow the instructions for recording to a specified track. You can choose any of the five melody tracks, but presumably you'll want to choose track 1.