If the lights should be permanently illuminated check the relay and/or the ignition switch. If the lights run from a handlebar or nacelle switch, check the switch operation. Also check for a wire break between the headstock and the frame; in the steering is where the wiring loom is flexed the most.
Spark plug gap for 1975 Honda CB125s is: 0.6 - 0.7 mm (0.025-0.028 inch) Ride safely Ahmet
130cc
0.05mm (0.002in) for both the intake and exhaust clearence.
I have been running a 1985 CB125S on unleaded 10% ethanol regular gas ever since I purchased it from a friend in 1995. As this is 2008, the bike has been run about 10,000 miles on unleaded and 10% alcohol fuel with no problem so far. So, CAN it run on unleaded? yes. mark
There is an idle adjuster screw on the carb, turn this a quarter of a turn anti-clockwise, whilst bike is running. You should hear it slow down, keep adjusting till you get it right.