First off it DOES fit. In fact, it fits too well that you will probably find it hard to screw on.
Rather than continue to force the stack onto the carb and risk screwing up threads I found my derbi FR clutch bell was the same threading. I used the nut to "chase" the threads on the carb and the clutch bell to chase the threads on the stack.
Little by little, back and forth, I was able to get it to screw on. Works on both my Arreche and Amal version of the same carb, 15mm and 17mm.
Was this review helpful to you?
0 taco eaters like this review
Velocity Stack for the WIN!
December 15, 2018
taco eater :
Derek from United States
By far this is the coolest part of my Puch. It's a kick ass velocity stack that cannot be beat. It added at least 23.4591 WHP. But really I bought this hoping the filter mesh wouldn't fly off the stupid plastic one kept on doing. It hasn't let me down and the ladies dig it.