[tomtalbot10589]

Is there and way to put a yoshi slip on to a fmf header?

 

[mrtheandrew]

an exhaust shop should be able to do it with minimal work... can't say for sure though.

 

[skier207]

I am sure there is but it would be a waste of time because the Yoshi's inlet is smaller than the FMF headpipe creating restriction. End result is, it probably wouldn't flow anymore than a stock head pipe possibly even less.