evinrude motor surging at full throttle, only run about 25 mph. I have new plugs my mixture is running very rich due to the knob for the low spead mixture is not hooked to anything that i can tell on examination.i know that my carburators each have 2 mixture screws was there at one time linkages between these 4 screws going to the lean knob on the front of the motor. i do not yet have a manual. I would also like to have the carburator breakdown or microfish in case these need rebuilding uptoitiam@netzero.com