( 2) Throttle body. Injectioneering does a modifica- tion to the throttle body that improves the first quarter turn of the throttle and eliminates flameout. I was skepti- cal before I tried it, but now Injectioneering owner Wade Wilcox is my BFF. This mod makes a shocking difference. ( 3) Cam. The CRF450 engine is a “Unicam” design, so installing a cam is notably cheaper and easier than on other brands. I was happy with the performance of the Yoshimura cam (read the test in the May 2010 issue of MXA), and I’m sure that vir- tually every aftermarket cam is a worthwhile improvement. The CRF450’s fuel injection has positives and negatives. On the positive side, it makes the bike very responsive at the first crack of the throttle, and it runs great down low. It makes the bike run better on cold mornings and on trips to higher-elevation tracks. It also enables more precise tuning, if you have the equipment and know-how. Negatives include a tendency to make the power flatten out on top, and flameout when chopping the throttle. And, the low-end bark is a negative for some. In fact, enough complaints were registered in 2009 that Honda tamed the mapping on the 2010 CRF450. Racers should learn to be careful what they wish for, because our 2010 was 1-1/2 ponies slower than the 2009. We blame the mapping (because it’s the only thing they changed). The following are the modifications I made in an effort to get the ponies back into the stable. (1) Programming tool. My first modification was supposed to be to the 2010 CRF450’s mapping, but first I had to make modifications to our PGM-FI tuning tool. It turns out that the 2009 pro- grammer will not work on the 2010 model because the connector, programmer and software are different on the 2010 model. Honda sent us the new software and an adaptive sub-harness (which costs about $100). On the positive side, the 2010 is way easier to connect it to. ( 2) 2009 black box. Since the 2009 was faster, and since it’s impossible to duplicate the 2009 mapping in a THE CRF450’S FUEL INJECTION MAKES THE BIKE VERY RESPONSIVE AT THE FIRST CRACK OF THE THROTTLE. NEGATIVES INCLUDE A TENDENCY TO FLATTEN OUT ON TOP AND FLAMEOUT WHEN CHOPPING THE THROTTLE.
LIVING with the HONDA CRF450
The Yoshimura exhaust gives the
CRF450 exactly what it needs:
mid-and-up power. The oxygen
sensor bung in the head pipe allows
for more exact fuel mapping.