Zip 2004 stem problem str8

bought an str8 stem to do a custom bar conversion on my zip but the bars won't stay inline!? have I fitted the stem wrong? I tightened the bolt up as tight as I possible can but the bars still move out of line!?

Someone please help me here

 

Had the same problem with the str8 stem adapters.
For some reason they won't fit piaggio's well.
I stayed with the standard bars in the end

 

how is it supposed to be fitted, do I just screw in the Allen key bolt I don't know how it works?

 

If you take off the top handlebar clamp you should see an allen key bolt that runs vertically down the adapter.
This tightens up the part that inserts in to the stem and expands to grip inside the stem.
A bit like fitting a bar end mirror.
Make sure this is loose when inserting it so that it goes down far enough to ensure the outer groove with the pinchbolt goes OVER the stem.
Once you are happy tighten up the inner bolt followed by the outer clamp bolt.
To answer your question there are 2 bolts to tighten. I suspect you are just tightening up the outside clamp bolt??

 

Ahhhh I see, the clamp won't go over the forks tho it just sits flush on top of it, the forks won't slide up into the clamp

 

Have you squeezed the clamp in not realising it was supposed to go over?
You may have to open it up a little. If you can measure the o/side diameter of the stem and compare it with the groove in the clamp and see how far out it is.

 

Right that's what I'll do thanks for the help

 

well.... the whole thing hasn't gone to plan, does anyone know where I can get a stem that will fit directly onto stock piaggio zip forks 2004? like a hebo stem or something or where to find one thx