Hi there from Holland!

Last week I set the ignition timing of our Beat., Bobby.
This was quite wrong. But when the ignition was good, the engine has no power between 1400-2500rpm.
I've put the igition ontime with a timinglamp but not use the plug in the how to.
http://www.manser42.freeserve.co.uk/page4.html
Could this really care so much? Now that the ignition is not on the right time, the engine do not have any power between 1400-2000RPM.
My feeling tells me that the timing belt is not showing up in time.

Any ideas?