hi there, i'm from malaysia, recently just bought a nc30, at first in runs well...but then problems come:

you see, my nc30 only run on 1 pistons because the other plugs are dead....i've change new plugs n it runs back but after 2-3 times ride the plugs are toast...at first i suspected something wrong with the carb and sent it to workshop to clean it, but it still the same, sent it back to change the pilot jet and main jet but it still the same too....is it the carbs?, ignition coil, electrical or what?....i'm getting nowhere......fyi, nc30 plugs are so rare here i've to go to singapore to buy it....and its not cheap....help me please

Are the plugs sparking, unusual for 3 to fail at the same time, normally only 1 and if it was coil, only 2 cylinders would fail
Check the fuel flow, a vacuum pipe from the rear head goes on the tap, it can split, and so can the diaphragm inside the tap.
Spin the engine with kill switch off and the fuel pipe disconnected to see if fuel flows.
If not, check vacuum hose and tap diaphragm for splits.

Dave.

arsey30 wrote:Are the plugs sparking, unusual for 3 to fail at the same time, normally only 1 and if it was coil, only 2 cylinders would fail
Check the fuel flow, a vacuum pipe from the rear head goes on the tap, it can split, and so can the diaphragm inside the tap.
Spin the engine with kill switch off and the fuel pipe disconnected to see if fuel flows.
If not, check vacuum hose and tap diaphragm for splits.

Dave.

But if the plugs are dead, it may be the reg/rec over or under charging the battery.

The charge rate has nothing to do with the spark intensity, providing that the engine is spinning over quickly, proving that the battery is well up.
The coils take 2 amps, the starter more like 100, the charge circuit can be removed and the bike will still run.
If the engine stops and then will not turn on the starter, then yes the charge circuit is fautly.
Dave.

Could be that the float height is out on the carbs, or pilot screws are too rich.

Than haynes manual shows how to set the float heights and has pilots crew settings.