F8B problem

2 problems:

- the battery gets charged with 15.5 Volts....too high! how to lower the voltage? and
- the choke seems to stay engaged for minutes instead for seconds, so the motor does not run well for minutes, sometimes for up to one hour

seems problem with part # 24? electrical valve ?:

see: Ya...TOR Parts

drawing seems similar to my Yamaha F8B motor.

is there a download possibility for a repair manual?

thanks a lot Charles