Once these two fuel-injected engines are running, there’s also a lot of difference in their character. The YZ has a very strong bottom-end punch and pulls hard through the midrange, but the power falls off fast on top. The CRF, on the other hand, is softer off the bottom but progressively gets stronger, pulling hard through the middle revs with a good punch on top. The instant snap that the Yamaha delivers is fun and helps the bike drive off corners, but the drop-off occurs so soon that it requires more frequent gearshifts.One reason for this difference is the bikes’ Keihin throttle bodies. The Yamaha’s is a 44mm unit, a smaller size that benefits lower-rpm performance at the expense of top-end power; the Honda breathes through a 50mm throttle body that helps the top end but at a slight cost of bottom-end grunt.