I've just bought a never used McAllister petrol chainsaw from Gumtree.It was in the box,and obviously never used. I've put chain oil in it,and fresh 40 :1 mixture,but it would not start.When I took the plug out and pulled the starter cord I saw there was no spark. I checked continuity on the on/off switch,and found strangely that there was continuity whichever position the switch was in(??).That was a disappointment,as I had hoped there would be the opposite ie no continuity & therefore there was the problem, but no. So I don't know where to go from here. Any suggestions anyone?