amal carb adjustment

[justin345]

i have a 1979 t140e with amal mkII 2900 carbs.  my spark plugs are covered in dull black carbon except for the side electrode, which is close to its' original color.  i assume i am running rich and need to lean out my mixture, but i am not exactly sure of how to do it.  i have the workshop manual, however i am unsure of how much to turn the adjustment screws.  any suggestions would be greatly appreciated.

[L.A.B.]

Under which running conditions? Full throttle? Normal running? Or just idling?

The pilot screws only affect idle mixture, as they are air screws then screwing them out weakens the idle mixture.

If it is running rich other than at idle then the rest of the carb settings (main jet/needle jet/needle position/slide cutaway and float heights) should be checked against the standard spec. And make sure the air filters are clean. One thing that has been known to cause rich running on Mk2s is that the rubber tips of the choke plungers can degrade and break up, so the plungers don't completely shut off the choke enrichment fully.  

Amal Mk2 setup and tuning info: http://www.hitchcocksmotorcycles.com/amal/mk2_conc_ht.html

As yours is the 79 E model which should have Lucas Rita electronic ignition then if you follow this procedure given for setting the carbs:
 "For setting the pilot, a fairly satisfactory method is to detach one spark plug lead, and set the pilot adjusting screw on the other cylinder as a single unit, it is important that the detached plug lead is kept earthed/grounded by fitting a spare plug to the cap and laying it on the cylinder head, otherwise the ignition system may be damaged.