i think i have now sorted it. i removed the plastic eninge covers to reveal a brittle old breather pipe, which had broken once, and the previous owner used electrical tape to seal it! needless to say, it is no longer sticky due to the heat/fumes
sadly whilst removing it, i broke it in another place, as it was so brittle!
the pipe was blocked on the air intake side, i am putting this down to the broken pipe. this will have caused pressure, causing the seal to leak.
i have fixed it with electrical heat-shrink for now, whilst i source a new one. although i have seen kits for £90 on the net, which i am NOT paying that for a piece of pipe and conectors.
the engine does not give off much smoke at all now. the only smoke that it is giving off is from the oil that has been there for a while, that i cant reach to clean