I have a craftsman lt-1000 with a briggs 31C707-0230-E1. Air filter filled with gas, so I took the plug out, fuel line off the carb, left the oil valve open for a few days. Installed a cheap new carb yesterday along with new filters and fuel line then put everything back together. At first the engine would surge while idling but it's smoothed out a little. It still surges, and throttle up stalls out with some black smoke. There is no noticeable difference between throttle in the center and all the way down (Throttle down worked properly before this). Max throttle stalls the engine and kicks out black smoke.
#2
cpurvis
Does this have a separate control for the choke? Or is the choke position all the way forward on the throttle lever?
If it doesn't have a separate control for the choke, you need to adjust the throttle cable.
Surging is nearly always because of insufficient fuel for the volume of air.
So either the carb main jet is blocked or dirty, float level is too low, fuel lines restricted, gas tank not venting or an air leak between the carb and the mower or blocked bowl vent.
with the engine running spray around the carb ( but away from the air filter ) liberally with some WD 40 or similar FROM A TRIGGER PACK. NOT A SPRAY CAN.
If the engine speed changes or it suddenly blows a lot of smoke you have an air leak.
Run the engine without a fuel cap to check for fuel tank venting
