Sea level to elevation

[MXDAD777]

I have an Alumaweld boat with a 2005 115hp EFI Mercury jet on it. It runs great at sea level where I live, but when I go up and fish the lakes in the mountains, it won't get out of it's own way. I know on a prop engine you can change the prop pitch for elevation, but what can I do with a jet? It's EFI too so I can't change any jets. Is there something I can do with the mapping or ???? Any help or insight will be much appreciated.
PS It cruises at 35mph at sea level but at 6,000 ft it plows water at 8-10 mph.

 

[Fishing Dude too]

Re: Sea level to elevation

Needs a different setup at 6000 ft. You go from sea level to over a mile high, comp loss, needs more fuel to perform.

 

[MXDAD777]

Re: Sea level to elevation

Is there something that is feasible to change like mapping or am I just stuck with it? It's not that big of an inconvenience at small lakes like Stampede, but if I wanted to go to a larger lake like Tahoe, it would be a major problem.