Mazda 6 Service Manual: No.5 engine stalls-after start/at idle

No.4 hard to start/long crank/erratic start/erratic crank

No.6 cranks normally but will not start

Other materials:

Mazda 6 Service Manual: Cruise Control (Some models)
With cruise control, you can set and automatically maintain any speed of more than about 25 km/h (16 mph). WARNING Do not use the cruise control under the following conditions: Using the cruise control under the following conditions is dangerous and could result in loss of vehicle control. ...

Mazda 6 Service Manual: Master cylinder disassembly/assembly
Caution If the master cylinder body is damaged, replace the unit as a component. When securing the master cylinder in a vise, tighten only the flange of the master cylinder. 1. Disassemble in the order indicated in the table. 2. Assemble in the reverse order of disassembly. Stop ...