John deer model Lt180 i did end up spraying starting fluid into the carb and it did turn over and run for about 10 sec and quit. i took off the vaccum pump and blew into each line and pu the vaccum pump back on the tractor. i sprayed a shot of starting fluid again into the crab it started and stayed running only if i held the choke all the way out. what is causing me to hold out the choke? if i release the choke, it quits.