Fuzzy black plugs
Appreciate the response...was not expecting any. Will give you particulars below.
The entire inside of the spark plug is covered. Insulator, electrodes, etc. The very tip of the central electrode shows where the spark has burned off the carbon.
Plugs are .035 gapped. Plug is fired by a Crane Cam points conversion ignition system (XR700) in a rebuilt distributer. New Coil, Rotor, Cap, Wires, gears, etc. Carburetor rebuilt. Have rechecked float adjustment a couple times. Timing 6 degrees BTDC. Vacuum advance seems to be working after slipping on hose and watching damper. Newly rebuilt engine by a notable engine rebuild shop here in Montana. Has 390 heads and has a mild performance cam.
Removed wiper hose at manifold to check vacuum. 15 inches. Seems low but have not had chance to trace. Engine starts without a problem. If it has been setting for a while it blows black smoke out the rear initially. Runs OK initially but then starts to rough idle. Have set and reset idle mixture screws. Tried to stick with the 1 1/2 turns that the manual suggests. Must be a lack of oxygen or too much fuel but can't seem to get to the bottom of what to change or try on the carburetor side of this.
Have checked voltages to coil, ballast resister is reading 2 ohms but seeing a drop to 8 volts when grounding negative on coil. (Trying to see if problem is in misfiring). The Crane Cam Fireball kit says to check for phasing (rotor and cap electrode alignment) Requires drilling a hole in the cap to view alignment with a timing light. Have not done this yet. Don't have an exta cap at the moment.
I am getting more than a little befuttled and frustrated. Just retired so I can spend a little more time on it until the snow flies. I am a little challenged until I get grounded with some knowhow on this type of thing once again. Been a while.
Ready to listen to the obvious wisdom that I respectfully have read in many of the posts.
Appreciate the response...was not expecting any. Will give you particulars below.
The entire inside of the spark plug is covered. Insulator, electrodes, etc. The very tip of the central electrode shows where the spark has burned off the carbon.
Plugs are .035 gapped. Plug is fired by a Crane Cam points conversion ignition system (XR700) in a rebuilt distributer. New Coil, Rotor, Cap, Wires, gears, etc. Carburetor rebuilt. Have rechecked float adjustment a couple times. Timing 6 degrees BTDC. Vacuum advance seems to be working after slipping on hose and watching damper. Newly rebuilt engine by a notable engine rebuild shop here in Montana. Has 390 heads and has a mild performance cam.
Removed wiper hose at manifold to check vacuum. 15 inches. Seems low but have not had chance to trace. Engine starts without a problem. If it has been setting for a while it blows black smoke out the rear initially. Runs OK initially but then starts to rough idle. Have set and reset idle mixture screws. Tried to stick with the 1 1/2 turns that the manual suggests. Must be a lack of oxygen or too much fuel but can't seem to get to the bottom of what to change or try on the carburetor side of this.
Have checked voltages to coil, ballast resister is reading 2 ohms but seeing a drop to 8 volts when grounding negative on coil. (Trying to see if problem is in misfiring). The Crane Cam Fireball kit says to check for phasing (rotor and cap electrode alignment) Requires drilling a hole in the cap to view alignment with a timing light. Have not done this yet. Don't have an exta cap at the moment.
I am getting more than a little befuttled and frustrated. Just retired so I can spend a little more time on it until the snow flies. I am a little challenged until I get grounded with some knowhow on this type of thing once again. Been a while.
Ready to listen to the obvious wisdom that I respectfully have read in many of the posts.
Comment