I have a 1997 Jag with 440 fan and single carb. When cold, I can only start the sled by dumping raw gas down the spark plug holes. I think the choke is not working, but no amount of adjusting the cable seems to make a difference. Really tight so the lever barely flips or really loose. Once started and warmed up, it seems to run fine. Any ideas on how I should troubleshoot? Thanks in advance.