My suspicions were right, the dyno guy put the O ring under the needle, rather than on top. Just finished putting it all right and raising the circlips one notch. Will see how it goes tomorrow.

Cheers for the help chaps.

Just a quick update. Last night I put on a new regulator and plug and had a good ride to work this morning. The fueling in the midrange is good with the drop of the needles and it pulls strong to red line. I can't imagine getting much better with standard needles than with the Kenso ones fitted.

I am a happy boy. Thanks to the forum for the help. What we do without these places?

Good to hear its running smoothly, what system are you runnng? When you get a chance could you check your jet size and let me know what needle position you used? I might have a go at using mine again one day.

I am running an Ethos full twin stack system. The main jet I couldn't tell you, as I only moved the needles, so didn't take the carbs off. The needle position is on the second from the top.