silver star clocks

[stephenh]

Hi all
i was out for a spin on a silver star[a friends] a couple of days ago when i noticed a problem with the speedometer and rev counter,while i was stationary at a jcn .....the rev counter needle was showing max rpm whilst the engine was only ticking over,and the speedo was showing that i was doing about 20 mph.when i pulled away from the jcn the rev counter needle began to move through the entire rev range of its own accord,has anybody else ever had this happen to them.Any help much appreciated. regards steve

[DAVID THOMPSON]

do a careful check of the electrical wiring harness
bad ground some where
sparkplug wire arcing to tack wire

start it in the dark on a very dark night and look for sparks ????

my rt125 tach went nuts one day the next day it died and i found the plug from the voltage reg unit
was burnt and a big mess
the speedometers most bikes often are an aluminium disc with a magnet in side
it is located close to the tach which may have been putting out big magnet pulses
as the electrical system feed it electric it did not like
i have been working on electric things 60 years and nothing surprises me any more
dave

ALSO SEE THIS

[comanche91]

Try this Steve:

http://www.mzriders.com/viewtopic.php?f=26&t=4508&p=23733&hilit=tachometer#p23733