Take a good run and pull all the spark plugs and read the color. They are your feedback. The emission equipment usually won't effect running except for being set leaner at the factory. But as you go up in elevation it should be richer.
Check for vacuum leaks around all the hoses and carb boots with carb cleaner at idle.

Maybe a good dose of Seafoam will help clean out some gunk.

 

I drive to 3950ft.,3/4 mile with no change, above that it might change.

 

Jets are not always installed just for changing pipes. Also, for changes in altitude, you should be able to use the air/fuel mixture screw to adjust for that, without having to tear into the carbs to replace the jets. I'm normally at about 4-5k feet in altitude, and ride up to the top of an over 10k mountain on a regular basis without all that trouble. You're probably going from close to sea level to about a mile up, so shouldn't be any different.

 

Air/fuel mixture screws only effect idle to about 1/8th throttle. Unless he plans on running around all day at 1/8th throttle I suggest he rejet if he's going to spend most of his time at higher elevations. Having driven in the Denver area in a carbureted car the loss of power is annoying.

 

The Honda Shop Manual indicates that when the vehicle is to be operated continuously above 6500 ft, each pilot screw should be turned in 1/2 turn. You could check to see if the pilot screw plugs have been drilled out exposing the pilot screws.

I don't have that exact manual but if the pilot screw plugs are drilled out, turn the screws clockwise until lightly seated and then turn out 1 full turn and that will be a good base setting. Non altitude setting is one and 1/2 turns out.

As pointed out the pilot screw is for low throttle positions and idle.

Your bike has been stored for a number of years with low mileage so I would suggest cleaning the carbs but agree trying Seafoam first may improve.


G.