I was thinking about rejetting my prairie and i have read alot of different sizes to use, and i also know it takes some experiementing, but just to get a benchmark what is common at 3000ft. i will have a muffler mod soon, and a k and n filter.

 

Do a search on jetting or you will get yelled at by the forum patrol! See my post from the other day.

Just kidding, but there is tons of posts you can read.

 

Matt! I am at roughly the same altitude, about 3000 to 4000'. . With my snorkel and twinair filter I'm going to try dynojets at 128/132. I'm currently at 124,128 which is too lean. Some would recommend staying with the stock Kehein jets. The 650 usually comes jetted pretty rich and I have a feeling mine originally was ok with the 138/142 jets that came with it but I had them removed and went to dynojet and am now too lean. Getting the right jetting requires some fiddling the screws that hold the float bowl on are very easily stripped. Another cheap and easy mod is the snorkel. It will let more air into airbox but I think the 03's already breath better then the 02's.

One thing I have noticed is that there arent to many 650 owners at the 3000' level, most are either well below or well above that altitude. I cant get at mine until April/May but keep posting your results. Nyroc is also gathering jetting info from anyone and is posting it as a guideline. Again I didnt see anything yet for the 3000' alt. Good luck.

Bob