| Author | Message | ||
     Jraice |
Just finishing a three day trip and confirming a problem I have had for many months. Bike seems to run poorly at higher altitudes but even just a few thousand feet is enough. New race ECM does it too so that's not the problem. Power goes down enough to make first gear wheelies nearly impossible. Also seems to mostly take power away under 4,000rpm. As I rev it up it feels choked out and right around 4k there is a small increase in power almost like a two stroke power band. Some sort of sensor failure?? | ||
| Iamarchangel |
4100 is the sweet spot, a bunch of things change there. Feels funny on the highway when it kicks in. | ||
| Gschuette |
I have never heard of this. A naturally aspirated internal combustion engine that experiences power loss as altitude increases? That's a brain buster right there. | ||
| Odie |
My 12S will lose some power up at March Badness. I'm at sea level (250') here in Alabama but Suches is 3000'. It is more than enough to make a difference. Thinner air; not as much oxygen. Our performance charts for a Blackhawk go in 2000' increments. However, a recomputation of performance figures is required when a change of just 1000' PA occurs. | ||
| Jraice |
Gschuette... Its not a straight power loss, its a loss under 4,000rpm with a sharp change. Guess its normal... My father said his Harley had no power loss at all. Even just a couple thousand feet seems to cause serious power loss, but only under 4,000rpm really. Guess its normal, just figured the ECM would relearn at higher altitude and give me less power but across the map, not just at 4,000 and below. At lower alt (home) it is a smooth power increase at 4K, no leap. | ||
| Gschuette |
I was just messin. When I lived in Utah I would take my bike from 6000 to 10000 and back again. It would run like crap for the next few days. These ECMs seem slow to learn in my experience. | ||
| Jraice |
Interesting I thought they were supposed to learn quickly. Guess I won't worry too much. My favorite track is low altitude  . | ||
| Jbolt |
I live at 4200ft and your right, it does feel like a two stroke. Kinda hard to do a wheelie at all. When I go to Sacramento (50ft) feels like it wants to wheelie every time I let the clutch out, gears 1,2,3. Drag and dirt oval racers out here tell me, at this elevation it's like loosing a little over 1 full point of compression. | ||
| Aptbldr |
Troy, Wisconsin, is situated about 850 ft above sea level. | ||
| Andymnelson |
do some searching on the board here- this topic comes up every once in a while. Do you ride at the higher altitude long enough for the ECM to learn? That seems to be the key. | ||
| Phazernut |
I stand to be corrected here but isn't the Race ECM preprogramed for a specific set of values and that's it. I read somewhere that with RACE ECM's they are programed for specific conditions. I read that its like going back to the carbed engines that must be rejetted with atmospheric and altitude changes. | ||
| Jraice |
Stock ECM did the same thing. But I believe the race ECM also learns. |
