MG Car Repair: 1979 MGB, air leaks, air leak

Question
Hi Barrie, The car had been storage over 15 years.  I had drained the gas, put in new gas, changed the fuel lines, and filter.  I cleaned and rebulit the carb and automatic choke.  I changed the oil, did an engine flush and changed the oil again.  I had removed the head and cleaned the valves, replace the springs and the seals.  While the manifold was off I cleaned this black, oily, sticky, hard substance out of the head, manifold and carb.  After putting it all back together, set timing, etc. I was hearing a "hissing" noise while my engine was running.  I removed the manifold and carb and found what appears to have been a leak in the right hand port (looking at the engine from the carb side) of the intake manifold. I noticed there also was again a sticky, gummy, hard, black residue in the port, and it also follows back to the carb, as well as running down the engine block.  It appears to be back, could it be from the manifold leak??? Any other suggestions???  Thanks for your help.  Ernie

Answer
Hi Ernie.  I am having difficulty picturing this.  A photograph would be very helpful.  

Some of these cars had an air pump and a gulp valve and an EGR valve and all manner of extra pipes and things.  I doubt that an air leak would produce volumes of sticky stuff so quicky.  More likely, it is sucking the stuff into the port via a hose.  Did you thoroughly clean or replace all the hoses in the fuel system?  Is the adsorption canister full up?  

As regards tracing air leaks, I find it useful to use a length of 1/2 inch heater hose as a stethoscope.

Hope this helps.
Happy New Year
Barrie