Thanks for the feedback norm and Jaffa. I'm still unsure of why norm means though.

Sorry should've explained. I ended up with two mowers from hard rubbish. The pics I took was the dirty of the two. The other mower, which I didn't take pics of, had a nice clean crank case and a plastic lid under the fly wheel where the points were stored. I threw those out and mounted a new ignotion module in there on one of the screw posts for the points. And I used that coii as it has the spade connection already and didn't require anymore mucking around.

The Prima cap is original. So I guess it's authentic Victa?? It didn't seem like anything wrong with it after a clean. So just replaced o ring on that. Yes, the needle is in with the pointy end down (or up). So the rounded end connects with the float. I checked this against other threads here and the service manual. However I did not replace o rings on carby spigot. Which I will do on the weekend.

Decompressor was stripped cleaned and rebuilt with kit. It operates as described on the forum here. When you suck on the nozzle the decompressor valve contracts and when blow into nozzle no air escapes.

so the engine. I stand there and pull and it does nothing. I leave it. Take spark plug out. Re assure myself I have spark. Pull the engine over a few times and the replace spark plug. Try and start again after three goes it turns over. I let it run for 10 mins. Stop it and then try warm starting it. It doesn't go. More mucking around then get it going again. Then try stop and warm start and it goes first pull. Let it cool. Try again and nothing.

So back to norms point, an air leak at the connection of the carby to the barrel reduces the suction and that could be the problem?? Is that how I understand it?

Also, the carby has been rebuilt as per instructions on the forum and Gregory's service manual. The carby is a LM carby. And no, I did not replace the black valve with a white valve that has lettering. The back of the carby though has that white adjusting screw which you can adjust the idle speed with.