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How does a Lucas MCR2
regulator work?


Solid state rectifier | FADE | Voltage | Adjusting | Temperature compensation 


These devices are generally very reliable and give years of faithful service. But the electrical contacts within do eventually go out of adjustment, and they are affected by moisture, corrosion, dirt and dust. The Lucas MCR2 is fairly tricky to set up correctly. But it can be done if you take care and approach it methodically.


The alternative is to remove the innards and replace them with a cheap and simple solid state rectifier. Our guide will show you how to deal with the Lucas MCR2. Take a look and see if you want to totally preserve the originality of your classic bike, or if you'd rather update this aspect of the charging circuit with a discreet modern component. It's your call.


We run bikes with both types of regulators. Just keep in mind that the Lucas MCR2 tends to fail slowly over weeks or even months. But the solid state rectifiers tend to fail instantly.





Remember to look at our Motorcycle Workshop pages too. We have more helpful tech tips there.



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