This is a Solex on a 63 Giulia Spider Normale. Carburetor works fine other than choke (starter circuit) not working. Have rebuilt & cleaned everything several times. Engine won't start with choke on. Need to pump accelerator several times to start engine, once engine is running, if you pull choke out 1/2 way, the idle increases (seems normal?). Go to full choke & it stalls immediately. Any suggestions of what to try next?