Thanks again Norm
My apologies for being a little slow getting back to you, and also for ever doubting you.
After your diagnosis was confirmed by someone else, (their post does not seem to be here anymore) I went and replaced the new primer cap and needle valve with the old one. (I did take the vacuum thing off and gave it a clean and ran a pipe cleaner through the throat while I was there). It started first pull, left it for a bit, started first pull and mowed the verge. I have tried it 3 more times since then, starts first pull. I have ordered a viton tipped needle valve but will wait until I have a problem before putting it in.
Next problem will be the shut off system, but I should be able to disconnect it when it becomes unworkable.
Again thanks for your help
