So I finally got my 90 super jet with 760 engine running good at the local lake with a msl altitude of 1000 ft. Today I went to silverwood lake and it was a disaster. The lakes msl alt is around 3-4000 range. From the moment I set it in the water it would not start. Then the new battery died. I jumped it from a boat and the engine fired right up and ran fine for the 10 min journey to the days camp spot. After 30 min or so I tried to go for another ride, it would not start. Then the battery died. I jumped it with a boat again and rode but it really bogged down bad, then it died. The plugs looked wet and black, oily. Was it the higher elevation that killed it? The carbs were tuned for factory specs around 1000 msl altitude. I tried to lean the bottom screws just a hair but it made no difference and I did not want to get the adjustments all screwed up. Thanks for helping.