Honda Turbo snowmobile that overheat

[imthemouse]

At my work We have a 4 year old Honda Turbo snowmobile only 190 miles on it, it has been in the shop more then on the snow, when it was used the first time it did grate after that it would overheat after 1 mile, if we idle it back it cools down if you keep it under 30 miles MPH. Honda won't work on it any more they say thy fixed it, Ha it still overheats. Our machine shop did ever- thing the THE Honda manual suggested that could be the problem, took it out & tested it, still gets hot, it is liquid cooled, has no plugged cooling lines, could the turbo system be the problem? they never want to look in to that part of it. so If anyone out there knows anything let me know.