I'm trying to get an older 8 hp briggs with the updraft carb I have a couple of these carbs and on one the needle for the float has what appears to be a rubber tip and I don't see a seat in that carb and the other needle is solid metal and I believe there is a seat in the bottom on that one, with the rubber tipped needle do I not need a seat? any info would be appreciated as I'm no mechanic but I have a few tools and just a little common sense but I'm hoping that will be enough to get the job done with a little advice, thank you