I have an 04 atv carb and a 07 dirt bike carb. why does the 04 have some type of pilot diaphragm and the 07 doesn't? Is the 04 supposed to have a hot start plunger? It just has a cap with nothing in the hot start hole. Its running lean and i found a missing o ring in the diaphragm and no hot start plunger in the hole. I'm thinking its def the problem.