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J.R. Buchanan


Slash Five Charging Voltages

August 2007

These measurements were taken on a '73 R75/5, after staring it with the electric starter, then riding it for a few minutes.

The charging system was recently checked for corroded connections, and one was cleaned, as it showed some signs of corrosion.

All RPM measurements were taken using the tiny, semi-reliable factory tach. Idle speed was too low to read on the scale, and 1000 RPM was hard to determine, as it was the lowest marked RPM, and the needle rested on the pin at this speed.

With the headlight on, the readings at idle and 2500 RPM were mildly surprising. Because of this, the measurements were made several times with the headlight on.

For information on how the charging system works, see the Bosch Charging systems page.

Headlight off

RPM Voltage
Idle 12.3
1000 12.9
1500 12.9
2000 13.2
2500 13.3
3000 13.3
3500 13.3
4000 13.3

Headlight on

RPM Voltage
Idle 12.4
1000 12.1
1500 12.3
2000 12.6
2500 13.2
3000 12.7
3500 12.7
4000 12.7