hi guys
i have some issue for my CBR nc 23 triarm
the bike only runs with 3 cylinder and it hard to start even with pull the choke
problem cylinder was the number 2 cylinder from right (in position ride the bike)
when the engine is on,i try keep the engine running idle for 10 minute but that cylinders wont run,exhaust pipe on that cylinder only warm

can anyone help me fix the problem...
and what the problem is....
thank you

If its definitely one cylinder not firing then it shouldnt be a coil problem. Ive had my nc run on 2 or 3 loads of times. Whack the plug out and see if its wet, then check it/clean it. It may be fouled. (may as well do all of them while youre there) If that doesnt work it whack a new set of sparks in. If you do the hold it against the head and see if it sparks trick, it doesnt seem to mean much on these bikes. The plug could still be breaking down under load. Could also be a ht lead broken/breaking down.

If the plug is dry then you potentially have a carb problem. (especially likely if the bike has been laid up for a while) The float could be stuck and not letting fuel in. Give the float bowls a gentle whack with the handle of screw driver. If still no good you may have a blocked pilot jet. ( does it run on 4 when you rev it past quarter throttle, or is it just an idle problem? If it doesnt run on all 4 at all then the carb may just be a bit gummed up and youll have to give them a more thorough clean.

Either way id say its worth trying a new set of plugs for the sake of a couple of quid each.

I have exactly the same problem with cylinder #2. I have new plugs in and I have removed and cleaned the carbs around three times. I think mine is still a carb problem though as I have pulled the plug and the porcelain around the electrode is white still whereas the other plugs are more sooted.

Any ideas anyone? I have tried tapping the float chamber. I have also tried revving higher and the only time the header for this cylinder gets warm is if I spray easy start down the inlet.

Thanks

mattj92 wrote:If its definitely one cylinder not firing then it shouldnt be a coil problem. Ive had my nc run on 2 or 3 loads of times. Whack the plug out and see if its wet, then check it/clean it. It may be fouled. (may as well do all of them while youre there) If that doesnt work it whack a new set of sparks in. If you do the hold it against the head and see if it sparks trick, it doesnt seem to mean much on these bikes. The plug could still be breaking down under load. Could also be a ht lead broken/breaking down.

If the plug is dry then you potentially have a carb problem. (especially likely if the bike has been laid up for a while) The float could be stuck and not letting fuel in. Give the float bowls a gentle whack with the handle of screw driver. If still no good you may have a blocked pilot jet. ( does it run on 4 when you rev it past quarter throttle, or is it just an idle problem? If it doesnt run on all 4 at all then the carb may just be a bit gummed up and youll have to give them a more thorough clean.

Either way id say its worth trying a new set of plugs for the sake of a couple of quid each.

thanks for your attention mate...
i have check the plugs and the HT lead and they have a spark
it still working on 3 cyl even i rev it quarter or half throttle
but the weird is before my bike has a problem like this,one day before i've ride the bike,when the engine is in cold temp only running on 3 cyl,but when the engine is getting warm they running on 4 cyl,when i test the bike on a ride,sometimes its running on 3 cyl and sometimes the 4 cyl is running again,i just cant figure it out what the problem is
im gonna check the carb soon
maybe im gonna ask u again if the problem not fixed

Check to see if there is an air leak around or a crack in the inlet manifold.
Over time the manifolds harden/perish or crack...or carbs just not seated properly
Lots of air,not much fuel= no go.
Hope this helps
Stimpy