HI I'm harold and I have an old Ariens snow blower 8hp that belong to my granddad and
Its knocking can you tell me what the problem could be I would love to get it up and running thanks hmartin

Harold, a knocking gas engine could be a bad bearing. Unless you know how to rebuild an engine it would be cost prohibitive to have it done at a shop. You'd end up with a new bearing and a very old carb, drive train, etc...