I have a 1990 mercury 90 horse, whenever I go to start it when it's cold, it will backfire out the exhaust. But whenever it finally starts and gets to running, it does not do that when I start it again. Any ideas what could be causing something like this? It seems I have to keep the choke pushed in for a while to get it started, not for sure if this something related to that or not. Any help is appreciated, thanks.
