It will be air that is your problem. I'm not sure what your black button is - have you tried screwing it down to see if it tightens? Make sure all the fuel line connections are good and tight - if not, the engine will simply pull in air through the 'leak' . Once your leaks are stopped the engine will pull fuel though and it will start!
Richard, January 2009
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I can answer this question...
i changed feul filter on 205 td m reg now it wont start?