I have a 68 40hp evinrude. It has been running pretty good the past couple of weeks. I just bought it about 3 months ago. I have always had to run it a almost full choke or it would stall and it always seems to spit and sputter at idle. The trouble is that the past two trips out it has died after about 20 minutes of operation, not wide open either. After about 30 minutes it will start again, but run rough. When this happens you can smell gas. The next day it runs fine. I bought a new fuel tank, in case there was a vent problem causing vapor lock, not it. I have got two opinions, one says electrical, the other says fuel system. Can anyone help me, I hate to start buying parts with no idea what is really wrong.<br />Thanks