I've got a Great Dane that I put a Briggs(not Vanguard)on. The other day I was loading it on my trailer and it started spinning real fast. I'm betting 4500 rpms. I thought it was going to blow. Long story short; I can hold the speed down by manuely holding the governer arm down but as soon as I let go it starts screaming. There are two springs that work to hold the arm down. Is there supposed to be one holding it in the idle position?