Nc30 only runs on 2 cylinders

[wambam87]

The story so far..

Old rectifier cooked battery + cdi , so have replaced all 3 parts now when i start the bike i get no rev counter and only runs on the rear 2 cylinders. is this its limp mode kicked in ? All fuses are new .

Any help as im loosing the plot !!

[wambam87]

Have just checked the plugs and im getting no spark to the front 2 cylinders

[tigerclaw]

I think thats a good thing, it is unlikely that both front coils have broken 9possible but unlikely) make sure they are getting power as a first point of call (likely they are not)... so hopefully its a power to the coil thing and not a coil things

[magg]

There is only one ignition coil per pair of cylinders. No ingnition coil and tacho signal after you changed the "CDI" suggests the replacement "CDI" is faulty. May be someone on this forum has a known good "CDI" you can try.

[wambam87]

After 3hours of tracing wires and searching, I've found that the 3pin alternator connector looks as if it has been burnt or shorted and 2 wires are visibly damaged. Could this be hampering power delivery to my coils?

[magg]

Unlikely, it should only affect the charging system.

If you want to eliminate the ignition coil as the possible source of your problem:

1. Locate the front ignition coil (front left side on frame), with the ignition switch in the ON position and stop/run switch is in RUN position, check that 12 volt is on the terminal with the black/white wire.

2. If 12 volts is present then turn ignition off and goto 3. No 12 volts, then turn ignition switch to OFF and using multimeter on ohms setting place one probe on ignition coil black/white wire terminal and the second probe on the Ignition fuse. Resistance should be 1-2 omhs, otherwise loom between ignition coil and power is faulty.

3. Using a multimeter on ohms setting place one probe on ignition coil black/white wire terminal and the second probe on the ignition coil blue/yellow wire terminal. Resistance should be 2-3 omhs, otherwise ignition coil primary is open circuit.

4. Using a multimeter on 200k ohms setting place one probe in one spark plug cap and the second probe in second spark plug. Resistance should be 25-30k omhs, otherwise ignition coil secondary winding or spark plug caps are open circuit.

[Neosophist]

After 3hours of tracing wires and searching, I've found that the 3pin alternator connector looks as if it has been burnt or shorted and 2 wires are visibly damaged. Could this be hampering power delivery to my coils?

Its common for that connector to burn, it carries a lot of current and if it gets dirty it will melt, best to renew it at some point but it shouldnt be affecting the spark as you can run the bike without alternetor.

It might be affecting the charge.

Start with a fully charged battery and do what magg has said above.

also check your charging system

[wambam87]

Thank you for the ideas guy's, can't work on it today, will give it a go tommorow. Am I right in saying that the Rev counter works off the ignition /spark of one of the cylinders? Could this be why it's not working as the front 2 are down?

[Neosophist]

many rev counters are driven off the nve from the coil.

the nc30 has a rev counter wire from the ignition box not the coil, which is why magg has sugested your igntiion box might be knackered.

could be plenty of reasons though, missing connector block, broken wires, or of course broken ignition box.

[Cammo]

Silly question perhaps, but have you done any electrical checks on the charging system after replacing your reg/rec & battery?