Page 1 of 1
Unstable idle speed nc30
Posted: Tue Jun 14, 2011 7:22 pm
by pns
Hi!I have some issues with the idle speed at my nc30.It goes from 1100 rpm to 1400 rpm and some times it dies.I run 120 jets front and 122 jets back.The pilot screw is set at 2.25 turns.I have drill the slides and change the inlet rubbers.I run a viper short can.I have checked clean and balance the carbs but i didn't see any difference.Do you have any ideas of what else to check?
Re: Unstable idle speed nc30
Posted: Tue Jun 14, 2011 8:03 pm
by Deviant400
when was the valve clearences done last , its best to re shim the the valves so there all within tolerence before balancing the carbs
Re: Unstable idle speed nc30
Posted: Tue Jun 14, 2011 8:16 pm
by pns
Sorry i forgot i have also done the valves before all the others.Thanks anyway!
Re: Unstable idle speed nc30
Posted: Tue Jun 14, 2011 9:00 pm
by jetblack
Airleak?
Spray some easystart or carb cleaner around the carbs while its idling and see if you get any change in the running.
Re: Unstable idle speed nc30
Posted: Tue Jun 14, 2011 9:40 pm
by lizard821000
does it bounce around?? or just start at 1100 then up to 1400??
id say airleak too , or adjust the idel/air screw
Re: Unstable idle speed nc30
Posted: Wed Jun 15, 2011 1:07 pm
by pns
lizard821000 wrote:does it bounce around?? or just start at 1100 then up to 1400??
id say airleak too , or adjust the idel/air screw
It bounce around.Well i should then check for airleak.I don't thing it would be easy to find where is the airleak but i will try.Thanks all for help.

Re: Unstable idle speed nc30
Posted: Thu Jun 16, 2011 12:11 am
by Cammo
pns wrote:I don't thing it would be easy to find where is the airleak but i will try.Thanks all for help.

You can easily check for air leaks by spraying easy start around the carb manifold rubbers, if the revs increase you have a leak.
I would be suspect of the electrical system causing this also. Do all the usual chrgaing system checks, check earth points also etc.
Re: Unstable idle speed nc30
Posted: Thu Jun 16, 2011 12:23 am
by zymon
thats a very interesting point viper - apart from checking the earth points and charging rates , anything else electrical wise to look into ? i put a mega beefy rectifier on mine which had two plugs on it - my bike charges back to batt at a healty 13.7v's or so , can you still have wires connected wrong in the two plug area if its charging right voltage back to battery?? One plug has two red wires and two white wires in it and the other plug has three wires on it ( which i presume is from the charge side of the stator windings ?? )