When changing my filters I typically get a few ounces of fuel spillage. Enough that I can catch it with a small container and shop towels. But on my most recent change on my port motor, the fuel practically gushed continuously until I could get the new filter spun on. Engine switch was definitely in the Off position, so fuel pump was not powered. I'm thinking maybe the fuel shutoff valve from the tank is stuck open? Any ideas how to test? Or other problems to look for?