I'm trying to get some help with a poorly running Case David Brown 885 G 3 cylinder gasoline tractor. It runs, but the exhaust has black smoke and sometimes when I start it, it backfires and sends out a powdery black soot from the exhaust. when I remove the plugs and check them they are black with this powdery soot also except for one plug in cyl 3 that appears a little wet with fuel. The compression is good, I think, at 130psi for cylinders 1 and 2, and 138psi for cyl 3.When it runs it sounds as if it is misfiring or not firing on all cylinders.
I have just renewed the Points, condenser, rotor and cap, made and tested new plug wires. Plugs are new.
Point gap is set properly, Dwell checks OK, as is timing when Timing pin is in SP hole.
Valves have been adjusted to specs in manual, intake .010, exh .007
I've rebuilt the carb, then changed the carb.
Voltage to + side of coil is 12.57.
If anyone has seen similar symptoms and has a solution please respond.
If there is any member who has one of these would you be willing to take some pictures of the Carburetor linkage and throttle linkage. I'm not sure how the linkage parts on the carb are supposed to fit relative to one another.
I have just renewed the Points, condenser, rotor and cap, made and tested new plug wires. Plugs are new.
Point gap is set properly, Dwell checks OK, as is timing when Timing pin is in SP hole.
Valves have been adjusted to specs in manual, intake .010, exh .007
I've rebuilt the carb, then changed the carb.
Voltage to + side of coil is 12.57.
If anyone has seen similar symptoms and has a solution please respond.
If there is any member who has one of these would you be willing to take some pictures of the Carburetor linkage and throttle linkage. I'm not sure how the linkage parts on the carb are supposed to fit relative to one another.