I bought a 1975 6hp. evinrude from a guy who is an outboard mechanic, it runs ok except when I shut it off an drift fish for awhile I have to choke it and it takes 3 or 4 pulls to restart. I called him and he said that that was normal for those motors. is this true? otherwise it runs good. also would a 3 blade prop give me anymore speed? it"s has a 2 blade on it.