Questionmy nighthawk seems to steadly running richer, inspection of the plugs shows black ring around the outside of the plug, and the electrode area is slightly white. I checked charging output at the battery, 13.5 volts around 2000 rpm I feel that the fuel im running is eroding the needle in the carbs , since they all show the same, and it has been increasing gradually... when i first got the bike, the plugs were gray evenly...
is there any other spark related items I should check?
I dont think wiring or connections are an issue.. but open to suggestions
Thanks, Frank
AnswerFrank, after 28 years, the carbs may need a good overhaul and seal/o-ring refreshing, along with a new float valve/needle.
Today's fuels, at least in the US are diluted with alcohol which is very corrosive to carburetor parts, including jets and needles, plus it makes the o-rings expand and degrade.
Your charging system seems to be fine, if it is holding voltage values around that level.
You could be getting some deterioration of the spark plug cap/resistors over time. If you have de-restricted the idle adjustment screws, you can try adjusting them a little bit. Overall, with the alcohol fuels down here, the engines are running too lean at higher rpms/loads, so I am jetting bikes richer now. If the needles are getting worn, it may be time to replace them and the needle jets.
Make sure your air filters is in good shape and drain the hoses below that collect crankcase fumes/solids, periodically.
Bill Silver
