Motorcycle Repair: cb500t, air mixture, bill silver

Question
greetings...after four hard years rebuilding a 75 cb500t which sat in a carport for 18 years ,only did 22000 miles finally got it started to find the left pot is running way colder than the right pot the idling is at 1100 rpm is there a standard setting for the air mixture screw like 1 and 1/2 turns from fully in ..2ndly the bikes horn is not working and the right side the starter button isnt...we cant parts in new zealand as they were only imported to individual people ...my question is there a work-around to get these going?
many thanks

Answer
Bruce, the factory book shows 1.5 turns out on the idle mixture screw.
If one side is not as hot as the other, then the cylinder isn't firing fully due to any number of factors:
Low compression... broken rings/valves not seating/clearances too tight.
Idle mixture circuit plugged/restricted
Idle speed arm screws not synchronized
Spark timing incorrect from side to side
Weak/defective condenser or loose wire connection to condenser/coil
Condenser not properly grounded to chassis.
Air leak at intake manifold
Fouled spark plug
Defective spark plug cap
Weak/defective ignition coil

With both handlebar switches inop, the usual fault is a lack of the ground connection
http://www.cmsnl.com/honda-cb500t-500-twin-dohc-k0-usa_model463/partslist/F++01.  #3
The handlebars are rubber-cushioned, so isolated from grounding to the frame w/o the ground strap. The switches ground each circuit to complete the functions, so with a floating ground, the circuits cannot complete their functions.

Bill Silver