scoobie1, you know I tested the 2057 quite a while ago with the B7-Pro and we felt that it softened the bottom too much so I decided to pass on offering it. The B5 is obviously a completely different animal with a lot more bottom end than the B7-Pro engine so it might be a good fit. This is another pipe that I need to pull in some more of and re-test with the new mill.

Regarding how it works with other Sirio mills this is a good question and probably not one that I'm going to be able to answer effectively. For the most part the only similarity between our engines and the Sirio engines is the carburetor and the fact that they are both manufactured for us by the same company in Italy. If you are running one of the Sirio engines your best bet would be to check on the Sirio thread. Also keep in mind that whatever information that you get , the performance of the pipe is going to be highly dependent on the power band of the specific engine model that you are using. So... make sure that you ask specifically about the one that you are running.

Regards,

Ron Hopkins
Werks Racing