well lads,,just a quick question id like to put out among ye,,are the plugs on the nc 23 easy foul,,,reason i ask is i put new plugs in the bike last week and during the week the bike was only running on 3 cilenders so today took the carbs off and cleaned them,,now the bike wont start at all,all its doing is giving a loud backfire every so often and will make a chugga chugga noise but wont fire up just like it used to do with the old plugs in it,,i think i may have flooded the bike aswell when trying to start it,,could the plugs have shat themselves so soon is wot im wondering,,ta for looking lads and all answers appreicated

make sure te ht leads are in the iright order

leads are on in the proper order,,the plugs r fooked,,i checked them today,,,,fookin sickened plugs wernt even a week old and had done all of zero miles

i would think your mixture is a bit rich, maybe just on tickover had the same problem on one of my 29's try settin up your idle circuit and probably new plugs (when you get back firing like you describe the spark is usually arcking across the plugs damaging them)
cheers tony

the plugs are just as you described scratchin,,spark is arcing across the plug and not between the electrode and plug,,,,,this mite sound dumb of me but how do i set up my idel circut or wot dose my idel circut consist of :)

this is a write up i found and i worked for me, but i did have to buy a carb adjustment scew driver
Post Re: carb set up

take the bike for a ride to warm it up.
When you get back home or to your shop, let the bike idle till the fan kicks on. We need to know that it is up to running temperature.

Shut the engine off.

One at a time, screw each pilot needle in till it bottoms (gently!). Then unscrew it 1.75 (one and three-quarter) turns. Do this on each carburetor.
This is a ‘known’ lean setting, but the bike will still start and idle.

Start the motorcycle and set the idle to approximately 800 rpm.

With your assistant watching the tachometer, SLOWLY unscrew the pilot screw on #1 carb till the idle starts to climb. Have the other person tell you when the idle starts up. At that point, start counting ¼ turns out. Your assistant is now watching for the tach to DROP a little. Once the rpm starts to drop, just screw the pilot needle back in half way to where it began to rise. You are setting the pilot circuit half way between ‘nearly too lean’ and ‘nearly too rich’.

Reset the idle back down to 800 rpm and repeat the adjustment on carb #2.
Repeat this process till you have adjusted all four carburetors.

Reset the idle speed back to where you normally keep it

Your pilot circuits are now set to optimum.

Take the bike for a ride and if you get popping on deceleration, unscrew each pilot needle an additional 1/8 or ¼ turn (just make sure that the additional amount is the same on all four carbs). Stop there. It’s as close as humanly possible to get it.

You have now set the pilot circuits correctly.

sound for that post scratchin appreicated im just waiting for the sun to start shineing here again and wen i get a new set of plugs il be trying that cheers