Yamaha Questions (Breather Valve- Spark Advance

[STO-Becky]

At the outfitters we have a 2008 Yamaha outboard Model # F4MSH SN- 1092673. We have been having problems lately and have a few questions.

1) What does the breather valve do and what will a bad hose or valve do to the motor?

2) How does the ignition spark advance work and where is it in the service manual?

3)How does the ignition spark advance work?

Rick

[boats.net]

Breather valve is the crankcase vent if doesn't vent then could blow oil out through seals.
Timing is controled by the TCI unit.

[STO-Becky]

Tci

It looks like we have a TCI problem, this controls the timing with the old one the meter reading was way off to zero and the timing light would not register. When we changed the TCI we could read the timing light, but the motor would still not go to a little only a little over 1/2 RPMS. Rechecked meter readings on the TCI and they vary from 1 Ohm to 15 ohms. Could this be a defective part? It was purchased from
Boats US.

Rick

[STO-Becky]

Hey, if anybody has any ideas about this I would appreciate the help.
Thanks,
Rick