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Motorcycle Repair/charging system


On 1998 Honda shadow 750 ace voltage goes down when I rev the engine what could cause this to occur?

Hello Oscar,

Have you measured the voltage at the battery? How low does it drop?

Usually when voltage drops as rpm rise, the problem is somewhere in the connections.
All of the charging system's components must be checked in the following order:
Battery (load test), alternator (no-load voltage), rectifier/regulator.

But first, measure the battery voltage with the main switch off, with the engine idling and with the engine at 4000rpm.
Get back to me with the measurements and I'll let you know what to do next.

Best Regards,

Motorcycle Repair

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Lazaros Ampatzidis


I can help you on EVERY issue involving POST-1980 Japanese Motorcycles plus KTM and Husaberg. My field of expertise includes Engine, Transmission, Fuel system (carburation & EFI),Electrics and Electronics. Maintenance, repair and tuning. Road and off-road suspension tuning. Please don't ask me about non-Japanese Motorcycle, especially American built on which I have low to zero experience.


I'm a rider and hobbyist since childhood. 25 years motorcycle workshop mechanic.15 years motorcycle racing mechanic. In order of experience high to low:Kawasaki,Suzuki,Honda,Yamaha,KTM,Husaberg.

Hellenic (Greek) Technical School.Internal Combustion Engines Engineer. Automotive Electronics.

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