No spark!

[ben_moto501]

Hi guys, My mate has an SJ 410 on a 'D' plate. The other day it spluttered for a bit then was ok, then it cut out and after that there was no spark at all! I have done a few checks that I know of and we have replaced the points, condensor and put another coil on it but we still have no spark! Using my multimeter there is power at the coil with the ignition on, there is a ballast resistor though so this is only about 5 volts... Is this correct? Any ideas would be very much appreciated!

Ben

[ScottieJ]

i think that sounds about right? or is it 9 volts that should be at the resistor???? i cant remember they are only 12v on start up IIRC

is all the timing set up correctly? points gaps set up correctly? tried a different dizzy cap and rotor arm?

[muddy kev]

check the voltage at the coil + terminal. should be 12volts with the points open. if its lower then theres a short to earth either in the coil or wire to distributor or in the distributor, could also be condenser although unlikely if been replaced.
make sure wiring connections on points/condenser not shorted down.
if u close points then voltage should drop, anywhere between 6-9 volts.
when u say no spark is that at the plugs or out of the coil as could be shorted rotor arm.
hope this helps.

kev

[ben_moto501]

How embarrassing!! It was something as simple as the rotor arm! I eventually decided to try mine as I thought it looked really grubby and it fired up first time! Note to self... Next time something happens check the simple things first!


Ben