Re: fuseproblems ! DADADADUM

• Author: K & R Tech (---.neb.res.rr.com)
• Verified User: rarexro
• Date Posted: 05-16-08 17:57

A moped magneto (without a battery) will definitely put out more voltage as the RPMs increase. For example, if a magneto puts out 6V at 3000 RPM, it will put out 12V at 6000 RPM (the mathematical relationship is linear).

I should really say that the magneto will try to put out more voltage. As the voltage goes up, the electrical load goes up faster (the electrical load is a squared relationship). For example, a 6 ohm resistor at 6V will consume one amp (6 watts). At 12V, the same resistor will consume 2 amps (24 watts). As the load goes up, eventually, the power consumption of the loads will exceed the capability of the magneto. In addition, if you have a battery installed, it also acts to consume more power as the voltage goes up – therefore, it acts kind of like a regulator (but not as good).

I recommend that you check your battery (if you have one). If it will not take (or keep) a charge, then you’ve lost an amount of regulation, enough to cause your problem.

As for your question, I doubt that you wiould run into a problem with a larger ampacity fuse, but the risk would be yours alone to take. I personally would not be afraid of installing a 10 ampere fuse, provided that it was a fast blow fuse (do not install a slo-blo fuse).