Arite I've got a big problem with my nc30 it's ran fine then about two months ago it started missfiring then kept holding the revs at 4000 I've looked for air leaks and striped the Carbs an cleaned them I've also put new plugs in it then tonite I've ran the bike for under 5 minutes and the front right hand side was glowing red hot all the other pipes are warm. If anyone can help it would be a big help thanx

you need to do the carbs properly- too hot = too lean. so blockages somewhere

Yes, very weak on that pot, but the others should be hot, not warm in 5 mins.

Look at pilot screw setting and pilot circuit on that carb.
Make sure carbs are seated in rubbers, top edge not trapped.

I've cleaned them with the air line loadz of time there's got to be sumthing else would they not need to be set up properly with the vacume gauges think thanx

make sure that your inlet manifold on the hot cylinder isn't cracked or split and the stub used for attaching the vacuum gauge is fully sealed. Running fast is an indication of an air leak

Josh312 wrote:I've cleaned them with the air line loadz of time there's got to be sumthing else would they not need to be set up properly with the vacume gauges think thanx

No, it's not balance, but weak [air leak] of blocked pilot [no mixture]

Do you remove the pilot screw and blow back towards the jet, and clear the 3 tiny holes in the main bore, next to the butterfly in the closed position?

i clean from both directions, to be sure, so from normal fuel feed direction going through all the holes/parts/jets in order as the fuel flows, then i do it in again in reverse , sometimes i even do it forward again too lol just to be sure.

Try a working set of carbs. Do you know anyone near you with an NC30?

Even if the balance is super super off that carb will just be getting less air (and less fuel as a result) but in the appropriate amount if the carb is working properly.

Your problem is exactly as arsey30 said.. the cylinder is too weak. Either too much air (air-leak on carb rubber)

or / including

lean carb.

This is due to either blocked pilot settings / incorrect float height / incorrect pilot screw setting.

Original fault was ticking over at 4000rpm, Current fault is glowing exhaust, both indicate weak.
Did the ex glow when the fault first occured, and does it still run fast now.

i.e. are we now looking for 1 or 2 faults.

Has the port balance adapter blanking screw fallen out, it's the long one that is easy to see as it is on the outside of the head, near the stat housing.