Gents, Yesterday in the mail I got my new Yosh TRC Stainless Slip for my 04 YZ 450. Installed it last night when I got home from work. Probably the best install I have ever done. Went on very easy and did not leak at the joint. I pulled out the spark arrestor since I will only be using it on the track. I like the sounds is diffrent sounding that the stock pipe. Yosh did not recommend any jetting changes. So I guess it is good to go. Looking forward to trying it at the track if this rain ever stops that we are getting in central florida. If your thinking about getting a pipe..this is a nice product! welds are great too.