Problems with jetting for altitudes would require smaller jetting than used at sea level in the same bike/engine combination. The higher the altitude , the richer the mixture would be with the same jetting in a carb.
If a carb used as a base line a #46 jet at sea level, chances are that you may need a #44 or #45 or even smaller depending on the altitude just as an example.
Here's a quick test that will tell you if you have to fat of a jet in the top end....
Run the bike through the gears into third gear and run third up to 60-70 MPH full throttle, then chop the throttle about 1/8 to 1/4 back and see if the bike either surges ahead or stumbles then recovers.
If it surges ahead, your jetting is lean
If it stumbles and recovers , your jetting is rich
If it makes no difference, you're pretty close.
As far as the low jet, generally if the idle screw is more than 2 1/2 turns open from lightly seated, the low jet size is generally too small and can be increased to the next size. A readjustment is then required repeating the idle mixture adjustment screw.
If a carb used as a base line a #46 jet at sea level, chances are that you may need a #44 or #45 or even smaller depending on the altitude just as an example.
Here's a quick test that will tell you if you have to fat of a jet in the top end....
Run the bike through the gears into third gear and run third up to 60-70 MPH full throttle, then chop the throttle about 1/8 to 1/4 back and see if the bike either surges ahead or stumbles then recovers.
If it surges ahead, your jetting is lean
If it stumbles and recovers , your jetting is rich
If it makes no difference, you're pretty close.
As far as the low jet, generally if the idle screw is more than 2 1/2 turns open from lightly seated, the low jet size is generally too small and can be increased to the next size. A readjustment is then required repeating the idle mixture adjustment screw.