Gday good people , I've nearly got this mower going I have plenty of spark and I may have a little fuel issue but I won't know till I find out a correct spark plug . It has a cj8 but the spark plug thread in the head is a longer thread than what is on the spark plug . So what is the correct spark plug to use?it won't let me upload a photo it says the entity is to large ,don't have this problem usually.