I just bought an 01 MC 600 carbed 2000 miles. The sled had been sitting for a couple of seasons. Cleaned out the tank, disassembled carbs and removed all the jets and cleaned. Sled starts easy, idles good and has good bottom end performance. However the mid range and top end is poor. Plugs are black indicating running rich. AC calls for 270 jets at 6000 feet and 0-20 degrees. Sled has 260's. I ride at 6-7 thousand. I noticed the air box boot does not fit the carbs. Owner added rubber donuts to make up the difference but the fit appears poor. Also there is a hole in the airbox behind the power valve server. Parts diagrams indicate a plug at that location. Is the airbox part of my problem or do I need to look further.
