this aint what you hope for.
the engines are designed to run properly at sealevel or up a few thousand feet.
a high altitude jet kit will actually lean out the engine.
think about it ...less oxygen further up you go .so engine requires less fuel not more.
thats why the folks climbing the high mountains carry oxygen bottles.
so unless the kit comes with an adjustable nozzle your in for a scorched engine.
bottom line is you wont find any manufacturer coming up with any legal way of selling you somthing to richen up your engine.
very large fines involved in that.
later chris
craftsman 10/28 snowblower with tracks husky 372xpg chainsaw sachs dolmar bc212 bushsaw mondo trimmer monster tractor with trailer cheep wheelbarro and couple shovels and a partridge in a pear tree