Super Jet PSI header

[alberta guy]

On my 92 650 the header coming out of the motor before the actual pipe says PSI on it? Looking through the forums i've never read about aftermarket headers. Just half pipes and full pipes. Because it also has a PSI halfpipe and pipe. Can anyone tell me more info on this?

 

[kevbo]

As I remember the early Protec pipes would bolt on the stock manifold, the PSI pipe may have as well. They were trying to keep prices low and in line with kawasaki pipes that didnt need an aftermarket manifold to run well. All pipe mfgs began incorporating their own manifolds for Yamahas since the stock one is not well suited.