what `s the gap size?

hi i have a mcculloch (electrolux) gladiator 550 petrol hedge-trimmer(2005)been having a bit off trouble starting it was in the shed for a little while been ok for 6 months with a few extra pulls but now primering it as normal and doing everything that you should with the proper mix there seems to be no sparking have the spark plug out thats very clean a little wet gap size is 60 is that right and if so what else could it be?,your help would be appreciated.
thanks john