Zebra's '04 DR650, 100% opening
|As below but with quiet insert removed, undrilled slide installed, float height corrected, and jetting corrected (at 100% throttle opening)|
|As delivered with FMF muffler with insert in place, snorkel removed, airbox modified, Twin Air filter, Uni under-diaphragm vent filter, drilled slide and non-USA adjustable jet needle (at 100% throttle opening)|
NOx measured ~1400-1800 ppm from 4-7K rpm with 91 octane fuel. I begin being concerned about detonation when NOx nears 1700 ppm.
As can be seen from CO trace, the mixture is still a touch rich from 2-3K rpm. While this type of thing is common whenever an airbox has been modified and a main jet has been installed that gives the correct mixture during high rpm WOT operation, it may be at least partially correctable with a fresh emulsion tube.
at 25% throttle opening
at 12.5% throttle opening
Wolf & Zebra