installed on a 2000 YZ125
First off, this pipe makes the power band much broader! I am very happy with this addition. I also added the Vforce3 reed block at the same time, so I would say these are two complementary add ons. I used the jetting specs that came with the pipe and I'm loving the broadened power band and crisp throttle response. I already had an FMF turbine core silencer, so I just repacked it before installing the pipe.
The install was very easy, and the pipe comes with orings already installed. I purchased the oring kit with springs just in case, but only used the springs so my old ones could be retired.
I was however, un happy with how the pipe arrived. There were some stains on the outside (pictured) that I would hope an expensive part like this would be free of before shipping. I cleaned most of it off, but signs still remained. I noted that the durability is not high because the pipe is larger than stock, and an expansion chamber is very vulnerable anyway, and can be beat up easier. Due to the larger pipe size, I also moved the kick starter back a few teeth to maintain clearance.