An added problem sort of on topic is a poorly programmed ECU if you're running an injected bike. '06 and '07 FJRs had a recall for the ECU. Original setup would read atmospheric pressure at startup, then assume it was constant. If you're riding in the mountains, you'd find yourself on a bum bike until you cycled the key to reinitialize the atmospheric pressure reading. New ECU map keeps atmo pressure sensor in the loop while running.

My 06FYZ R6 with PowerCommander 3 usb handles it all automatically very well. Only difficulty I experience is automatic choke produces very hard start. Once running all is puuurfect at any altitude [so far ranging from 6k to 1k].

Back in the day the quick easy method was 3 laps, pull in, and perform "plug chop". Adjust jetting to "light brown color" [not applicable with certain head modifications which require rich mix] and bottom rpm of power band during 3 lap test. Most often, ambient characterists could be taken care of by spacers on the needle jet. Everyone suffers power reduction with extereme saturation high ambient days. No cure as far as I know. My recommendation: dial it in at your altitude and then only adjust one main jet up or down. Use the needle jet to optimize after that. Slow jet should be richened 1/2 to 1 full turn or size [whichever] over stock setting.

Fuel injection: Dial it on your home track and leave it alone.

IF you have FI on your Duc Shouldn't the mapping on the FI compensate for altitude or is Ducati Leaning out the FI to comlply with emissions? or msybe the high altitude is too much for it.
BTW Darby,
Did you happen to put the "Race Kit" your bike prior to Laguna?
I'm told the 1098 has different mapping if the track/race kit is installed.
I know some Aprilla's can gain quite a few HP if a certain
wire is cut.....

Surprised to see this thread is still here.

I recently had the bike done up with Termignoni slip-ons and the furnished/required ECU, then dyno tuned. Shows 144 HP and is definitely stronger in the mid-range. Sounds delightful too, of course.

I was told that the stock ECU is set up for Euro emissions and doesn't squirt enough fuel for best performance.

The new Aprilia was unveiled at Miller - slick bike for sure.

liljohnnie69 - 06 February 2009 01:45 PM

With the advent of fuel injection this discussion will soon be obsolete to all but the most diehard carb fans

EFI helps compensate for a proper air/fuel mix at different altitudes.

But even with proper jetting at altitude with lower density atmosphere there will be a corresponding power loss.

Yep -- Less Air = Less Power