Just tested my fuel (some bought months ago and some bought yesterday from the same place) and it showed 10% gasoline! I have had a lot of trouble tuning in 2 NA engines. Both want to die after a pass but will re-start after 30 seconds and run OK and both are garbely in the mid range but seem ok at top end. From what I have read E90 would cause a lean condition as compared to E85. Both engines were dynoed and ran OK there but in the boat had trouble. Maybe the dyno fuel was E85 while the boat had E90? Could this be the cause to my problems?