Tohatsu 2.5 doesn't want to suck in fuel mixture into cylinder

[maartenroelofs73]

Hi All, hope someone has a brilliant idea..

I havea 1996 tohatsu 2.5 (similar to the yamaha, mercury, and many more, based on the same system). Its overhauled, cleaned and all fresh.. but.. It seems not to suck in a stream of vaped fuel into the cylinder.

Strange thing: when I blow air from a small compressed bottle, it will start for a few strokes, then quits. So ignition /spark, all seem to working well. We've re-done the gaskets and it should be airtight (so to build a vacuum, which then should suck in some fuel/air mixture.

Carburator gets in fuel, the needle is clean, and idle screw wide open. Anyone have experienced this and found a solution or reason to this? thanks!