Small Engines (Lawn Mowers, etc.): Craftsman

Question
QUESTION: I have a craftsman silver 5.5 hp lawnmower with a pulsa jet carb that is only a few years old.  Starts on first pull and runs great but while cutting the grass it will suddenly sputter and blow black smoke then just before it stalls it will smooth out and run fine again.  This will happen the whole time I cut the grass.  I have a fairly small yard that takes me about 20min to a half an hour to cut.  I have pulled the carb and cleaned it.  Took out the fuel and air filter and cleaned them.  The diaphragm seems to be ok.  I even changed the spark plug nothing makes any difference at all.

Any ideas??

Feeling next to useless

Glenn

ANSWER: What is the engine model, type and code number?

Does your carburetor have a primer bulb/button you push 3-5 times to start cold?

Let me know.
Eric

---------- FOLLOW-UP ----------

QUESTION: This is what I can find.

Craftsman
Briggs and Stratton
Silver
158cc 5.5 Ft lbs torque
Model # 944.361180

Yes it does have the primer bulb/button you push 3-5 times.

Hope this is what you need

Thanks

Glenn

ANSWER: Please re-check the model number.  The format seems correct but I can't find the model number.

If you Google the model number you should be able to pull up the parts diagram on Sears website.

Let me know if the model number is correct.

Eric

---------- FOLLOW-UP ----------

QUESTION: Hi Eric

I verified the model number and it is correct.  I called Sears and they told me that because it is a Canadian lawn mower that I won't find manuals or parts breakdowns online.  Is there another way to do this?  I could send you pictures or explain in more detail as to what you need.  I have a strong technical background in the automotive industry so terminology should be a problem.

Thanks again Glenn

Answer
Does the carburetor prime correctly?  Does the primer bulb squirt gas?

Is the fuel intake pipe sealing?  Is it possible warped?  You can use a little Permatex 2 to ensure there are no intake leaks.

Some of the older fuel tanks would warp a little over time and cause your symptoms.  If you take the carb off the tank you can use a flat file and run it across the fuel tank base in a couple of different directions to see if it is warped.  If shiny spots are present over the entire base after a coupe of strokes the tank is not warped.  If you see shiny and dull spots then the dull spots are low and the take is warped.


Eric