I recently bought a pair of 2000 700 Summits with 151 finger tracks. I purchased them from the same individual so I got the history on them. Mind you I was heavy into snowmobiling from the mid 90's to about 08' when I sold my Rev. I need to do some tuning on the one I ride because the one my boy rides just eats it alive. I know the one I ride is lower geared but even out of the hole it just doesn't pull that hard. It has an Arctic Cat secondary on it but I am not sure what helix or spring it should have for that sled. We ride from about 4000ft up to 8000ft. I cannot find a lot of information on where to start this tuning process. I talked to the local Doo dealer and even tried to look up some references from the days of old when I was heavy into it. What I have found is most look at me like I am working on a the first Ski-doo built or they are out of business. I didn't think 16 years was that long ago. Any information or direction would be appreciated.