My 2004 R50 manual transmission , 115,000 miles. had an intermittent starting problem. Now the Coop will not start at all unless I place a magnet next to the Clutch Switch.

For awhile the Coop would not start with the clutch depressed. I would have to attempt to start the Coop multiple times before the Coop would no longer start. During the intermittent starting phase the Cruise Control would not engage. I could turn on the Cruise Control, but when I would attempt to set a speed, the Cruise Control light would flash twice and then go off.

Now the Coop will not start at all. I looked through the postings online and found the problem could be the Ignition Switch (61-32-6-913-965) or the Clutch Switch.(35-42-6-876-898). I replaced the Ignition Switch with no success. I replaced the Clutch Switch and also had no success in solving the problem.

I then learned that if I place a magnet next to the Clutch Switch, the Coop might start. Success.

The placement of the magnet next to the Clutch Switch which activates the starting sequence, tells me that there must be a magnet in the Clutch Switch or Master Cylinder (21-52-6-774-078) that actuates the Clutch Switch when the Clutch Pedal/Master Cylinder are depressed. Looking at the Clutch Switch and checking for a magnet showed there is no magnet in the device. This means the Clutch Switch is simply a Normally Open switch

This also means there must be a magnet in the Master Cylinder that should move with the depression of the clutch pedal that activates the Clutch Switch to a Closed position, thereby activating the start sequence. Looking at the Clutch Switch, there appears to be four wires, which may mean the switch actually has two contact switches. One switch for the Starting sequence and one switch for the Cruise Control sequence. This would make sense because the Cruise Control no longer turns off, nor does it set a speed, when I attempt to set the cruise control..

The picture below shows a paper clip hanging from the Master Cylinder from a magnetic force. When I depress the clutch pedal, the magnetic force does not move which indicates to me the magnet is hung up or broken free.

Can the magnet be repaired or does the Master Cylinder need to be replaced? Am I incorrect in my observations and presumptions, and do I need to check or replace another part?

 

Yes, your observations and presumptions are correct. But before throwing a new master cylinder in there check the power and ground to the switch.
Unplug the connector and with the ignition on you should get 12V on pin 3.
Pin 1 should have almost no resistance to ground.

 

Is 12V on the #3 and ground on #1 a mute point if the Coop starts with a magnet next to the Clutch Switch?