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Old 19 July 2013, 03:58   #11
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Quote:
Originally Posted by Locozodiac View Post
Some engine manufacturers sells high altitude carb kits,
And if it's an oldschool enough Johnsorude it has the mixture controls on the front panel for easy adjustment!


Do the new fuel injected machines auto compensate?
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Old 19 July 2013, 08:34   #12
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Oops my mistake, the chart I checked must have been meters and not feet as it showed half an atmosphere at 6000! I was both surprised and tired.
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Old 19 July 2013, 09:00   #13
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Yep, 4x4 petrol non turbo car I once hired in the swiss alps had practicaly no performance left at 2800m. Road bike in Spain (118mph in second gear) felt hopeless on top of one mountain road there.... (would still go quick, but felt really flat)...
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Old 19 July 2013, 11:49   #14
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Yes. I deflated the tubes several times climbing up the mountains and will have to stop several times to inflate them on the way down or they get too floppy. I made this same trip last year but not for so long. We also have various temperature changes to deal with. Driving around California I can see 50F temperature swings. That tends to make the tubes change dramatically also.

As for power we are getting by. We are only here for another day so I didn't change props and its only stalled once or twice. I saw that even the super charged Verados suffer from power loss but only about 1/3 of normally aspirated.

Jason
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Old 19 July 2013, 12:34   #15
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Do the carbs have slow running screws , they normally work on the fuel side on 4 strokes so half a turn or so in would improve the bottom end running and first part of the throttle . Quick fix and easy to put back to as it was .
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Old 19 July 2013, 13:11   #16
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It's just not worth messing with. Only one more day on the lake and that will be at idle for the most part pacing swimmers across the lake.
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Old 19 July 2013, 13:19   #17
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Quote:
Originally Posted by 9D280 View Post
Do the new fuel injected machines auto compensate?
Yes but there's just not enough oxygen to create the rated horsepower. My 60hp was about ~44hp at 7800ft elevation. The worst part was that it was still propped for 60hp so waaay over-propped and only reached about 4500 rpm instead of 5900 at sea level.
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Old 19 July 2013, 19:20   #18
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Quote:
Originally Posted by Luv2Fly View Post
Oops my mistake, the chart I checked must have been meters and not feet as it showed half an atmosphere at 6000! I was both surprised and tired.
Easily done!
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