no spark

[manxr65]

well after many hours of messing with carbs i now have no spark , when  i turn bike on and off it sparks on both plugs but when turning over theres nothing . any thing i can go at to check , i have checked points which are ok , all grounds seem ok .
colour of the  spark is a yellow colour , i have power as far as the trigger unit ( the little silver box ). beside the relays .

[Bob_Roller]

The color of the spark is a bit of a clue, it should be a blue to white color .

When you turn the key on, what color is the spark ?

When you use the starter it draws a lot of power from the battery, if the battery is not in good shape (old) it may not have enough power to operate the ignition system .

Another possibility is that the starter is 'dry' it may need to be disassembled cleaned and all of the lubrication areas refreshed .

Place  the leads of a voltmeter to the battery terminals, operate the starter and see what kind of voltage indication you have while the starter is operating, this needs to be done on a fully charged battery .

The battery voltage should not be below 10.1volts, after 30-45 seconds of starter use .

If I'm not mistaken, you have an aftermarket 'electronic' ignition system added to your points type ignition, you may need to get a trouble shooting guide if it is suspect .

[Barry]

If you have points and a "little silver box" near the relays then I agree with Bob that it sounds like you have the early points ignition with an aftermarket ignition amplifier fitted.

It would be very easy for you to eliminate the silver box as the possible faulty item and change back to stock points ignition by moving only a couple of wires and maybe adding the condenser. You should be able to identify the wires in this diagram if your wiring harness is original.