Weekend motorcycle trip

[Pilgrim]

It's actually very common on small bore 2-strokes.  The guys who ride in the Rocky's deal with it all the time.  It's a frustrating science to get it right...temp, humidity, altitude all take their toll on the performance.  That's why I usually bring 2 - work on one after the last run of the day.

Here in the Rockies it's not unusual to go from 5,000 feet (Fort Collins) to Estes Park (40 miles) at 7500 feet, and if you go into Rocky Mt. National Park you can be over 9,000 feet....all within 90 minutes.  Pretty tough for any carbureted vehicle to deal with that much altitude change.

The town of Breckenridge where we often ski is at 9600 feet...like most of the access points for ski areas here.