Steve, as you know i ran a single 40mm dellorto on #1 SRX6, on the standard fuel tap, I just blanked off the vacuum pipe on the tap (wasn't a take off on the manifold or carb), and ran the tap in the 'prime' position......worked fine. I'm now running 2 x 34mm dellorto's on short(er) rubber manifolds and currently no air filters, using the same 'prime' tap setting....also with no problems, however i do have an annoying mixture problem, seems to run rich below 2000rpm, and leans out as the revs increase, and is fine maintaining say 80mph, if i wind it up from there i feel the mixture gets increasingly weak as it seems to lack the grunt and top speed you'd expect from a 640cc engine with extensive head work, twin 34mm's, high compression piston etc. But i would have thought with ANY setting of needles/jets your bike should at least start......i bought my carbs on Ebay, supposedly off an SRX6, and they just wouldn't perform....max 3000rpm, then only if you opened the throttle VERY slowly, so got a boxful of jets and needles from dellorto and played around, think the next thing is an hour on a dyno to get it completely right....my point is, with the carbs hopelessly out of spec for the SRX6, it did still start...and run after a fashion. My 2 track bikes run 36mm amal monoblocks......well...they just work :-)
Good luck.....not much point in giving you the needle/jet details on mine, although very similar to the kehins, would be a bit of a red herring i think.
Oh........ever heard of the 'Reece Fish' carb? bl**dy fantastic bit of kit, used a pair of them on a 1275 Cooper S i used to race (when i was young good looking and single lol ) point is...I've still got them.....often wondered if i could bodge 'em onto the SRX...
pip pip
