"David.... The slow speed need
"David.... The slow speed needle valve is the long brass threaded rod that is inserted into the topfront center portion of the carburetor. Normally you will not see it due to the plastic protective air cover secured to the front of the carburetor.
If you remove the screws that attach the top plastic portionof that protective cover, it will be obviously visible.
If you have compression (check it), what is it the reading of each cylinder?
With the spark plugs removed, the spark should jump a 7/16" gap with a strong blue lightning like flame..... does it?
If the two above areas are as they should be, I could only assume that whoever you had work on it is not fully certified and knowledgeable of the carburetor's operation (it happens).
Let us know what you find pertaining to the compression and spark.
Compression gauges are cheap.... Wal*Mart, K-Mart, any automotive parts store, etc.
Spark tester......
(Spark Tester - Home Made)
(J. Reeves)
A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas the!y could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
..........X1..........X2
.................X..(grd)
..........X3..........X4"
