anyway, after getting my new mini back via trailer we thought we had sourced the problem of the strange popping and backfiring through the carb to be the timing, as the dizzy moved, so we put it back to the right place, and then put the needle back in the piston, as it fell out
we also fiddled with the mixture (but we didn't know what we were doing at the time 
)it ran really great after that, but today when testing out the brakes it started doing it again, it gradually gets lumpier and lumpier. you'll get very fast but small popping (sounds like a chevy V8) then it will gradually get bigger and slower until the engine dies, all this backfiring causes my faulty needle to come apart again (i will get a new one, promise).
anyway, the dizzy hadn't moved this time, we marked it. the points are gapped correctly and it has had a new condensor and points just yesterday.
eventually, we got it to the point where it idled, albeit it horribly, just through persistance, then my dad fiddled about with the mixture and it was perfect again????
so to the point, why would the mixture keep changing?? what would cause it to adjust itself, it tends to do it after quite hard acceleration if that helps?
it's kind of a win/lose situation as we're happy we found the problem, but im annoyed as i know it will probably happen again and we don't know how to stop it
as i said, any help appreciated
M
