Tried searching, but no avail. Got an almost new Briggs 8hp on a Troy Bilt horse that won't stay running unless the choke is constantly switched on/off and when so, it runs pretty rough. When you let go of the choke no matter what position it is in, it will die unless switched back and fourth fast. Took out both adjusting screws and the tips are pointed but then flatten out at the bottom rather than being pointed like a needle. Does this have anything to do with the problem? Model nbr is 194412- thanks.