Originally Posted by creaven
hey guys can some one try help me here i cant remember if excessive blue smoke means too rich or to lean mix ? looked on google and cant find the answer. i have tried to play with the top end needle but it ether stalled or started bringing way too much petrol through .
If you tilt the car and excessive oil and fuel pours out of the exhaust pipe then it is too rich and it can harm your engine as compressing a liquid rich mixture can harm your crankshaft, bearings and connecting rod.
If you remove the glow plug, crank the engine and fuel sprays out heavier than a fine mist, then put the plug back in, turn the TOP needle clockwise in 1/4 turn increments until you feel the engine improves in performance and less fuel exhausts, then it's a matter of very minor adjustments. The top needle is the primary valve for fuel flow.
If your engine runs very fast at top speed with little smoke, this may be a IDLE mixture issue or the "bottom" needle and isnt as bad but still can cause problems. The screw/valve is usually at inline with your carburettor cylinder either front or rear. This valve in most cases is directly related to the idle screw and is more difficult to tune.
If it's just an old engine and blowing smoke without excessive fuel / air mixture richness then it's ok, leave it as is.