Ossa And Altitude Changes

[lankydoug]

Does any of the new Ossa owners have experience with riding at vastly different altitudes? Do you have to reprogram the fuel curve when you drastically change altitude? Can you make adjustments without owning the programming equipment or making a trip to a dealer?

[markjw]

hi Lankydoug

There should be no need to do anything. With the bike being fuel injected, it does the fuel/air automatically

I live near Canberra, Australia - altitude 550m, We had a trial at a town called Nimitabel, altitude 1100m, bike needed no changes, ran the same

[toothandnail]

That's good to know , I ASSUMED it would be the case , as is with my other FI bikes. We ride at 900 feet most of the time but go to 11,000 sometimes ^{when making that drastic a change their hard to start but run fine after.}

[tomch]

Bought a completely bog standard bike assume set by ossa factory in Spain.... Ran very well at 5000 ft asl and then took it back home at 6500ft asl- where it also ran perfectly. I'm up to 9000 ft and above in a few weeks time and will let you know how I get on. At 100:1 very little smoking and bogging but it does like to be cleaned out a bit if it is to start in 2-3 kicks from cold.

[lankydoug]

If you can go from 900 to 11,000 feet on an Ossa without having to make a change that is a big selling point. Some of the FI four strokes will do fine to about 8,000 but at 8,000 and above they start getting rich and lazy and tend to foul plugs. 550m to 1,100m would not be much problem for a carburetor either, maybe only requiring a tweak of the air screw.

[lankydoug]

hi Lankydoug

There should be no need to do anything. With the bike being fuel injected, it does the fuel/air automatically

I live near Canberra, Australia - altitude 550m, We had a trial at a town called Nimitabel, altitude 1100m, bike needed no changes, ran the same

What live data input does the Ossa system use to adjust for altitude? For example FI automobiles use exhaust oxygen, exhaust temp, throttle position, manifold vacuum, baro pressure, sometimes intake air flow, intake air temp, engine rpm, all this and possibly one or two I forgot to list are calculated about at approx 30 times per second and fuel and spark timing are adjusted accordingly.

Anyone know how Ossa does it?

[toothandnail]

My other FI bikes just use BAR and temp , combined with a fuel map. works great. But like I said when hauling from 900ft to 8000ft they are hard to start , same when going back down . While riding , alt. changes are not noticed. We varied from 6-9500' with no problems , 9500' has a noticable loss of power over the 900' at home.

Edited April 9, 2012 by toothandnail