do the wipers come on otherwise? if so it could be a problem with the multifunction switch(the one that controls the wipers, signals, high beams etc) or a relay for the wash mode
take the fuel line off the carb and turn the key on and see what kind of fuel flow you are getting. would be even better if you have access to fuel pressure gauge to check it properly. if you' are not getting much fuel coming out there then change the filter under the frame and you may also have...