Charge and check your battery. Charging systems in these bikes are notoriously not amazing. Nighthawks have electronic ignitions which controls idle speed automatically. I.e. if the battery power isn't there, theres no idle = bike dies. Might want to look into a new voltage regulator if problem is persistant. Or, just use a battery tender frequently.
Hope that helps.
Andrew
In hot weather my Honda Accord 2000 starts but idles rough and dies.
It was the PCV vaule
my 1988 4ws Honda prelude idles low at 600 rpm
idling too fast - adjust choke
It's OK for your bike to idle high, briefly, as it warms up. Just move the choke to the half-way point or so before taking it off completely. A gradual reduction in the choke will make shut-offs less likely.
If the plugs, plug wires, are good then suspect a vacuum leak somewhere.
The vacuum pull off for the choke on the carburetor may be bad or out of adjustment.
incorrect choke adjust ment. when cold if choke is working correctly the car will idle higher until warm enough for the choke to release. It Depends on the year of the car as to whether it has a choke or not. If it fuel injected it will not have one. If that is the case it could possibly be due to a coolant temperature sensor. If there is a check engine light on,it would be best to have the computer scanned for codes.
You might check to make sure that the choke is not staying partially closed. That will cause these symptoms. Also, make sure you have a clean air filter.
Perhaps throttle plate is stuck open - try to free with a screwdriver
in park my 94 honda prelude 2.3 idles at 4000 rpm what can i do to slow down the idle ? <><><><> Idle speed is controlled by the computer, and is not adjustable. You have a problem with the computer or a sensor. Take it to a shop.
replace the thing its faulty dont try do fix something you dont understand