A similar question recently came up here. Maybe the replies to that will help.
Thanks Darryl, The post you referenced was leading in the direction of the choke. I forgot to mention that this engine is in an Exmark Laser Z. The choke and throttle on this machine are on separate controls. I have checked for full choke with the air cleaner off, and it seems to be working OK. When getting ready to run this machine for the season, I think I will open the float bowl drain before cranking to see if there is any gas in it. Thanks again, Don