What would cause this?

[Paulmuphesto]

So i finally got my bike up and running again, for those who read this thread http://gstwins.com/gsboard/index.php?topic=34075.0

i basically emptyed and cleaned out the petrol tank, took out the carbs and sprayed them with carb cleaner (making sure i got in every hole etc)

Put the bike back together and it worked so i took it out for a spin (5-10 mins) and it worked fine.  Couple of days later i take it for its M.O.T (Uk people will know) and as i was driving it seemed to be working ok at low revs.  However, when i tryed to rev up/accelerate fast it was not doing so.  It would get to xxx amount of revs and not go any further, then backfire and the engine would kick into the revs it should be at.  (i.e. get to xxx revs and accelerator keeps turning but engine does nothing, backfire, engine kicks in at xxx (+extra) amount of revs)

Bringing the bike back home from the M.O.T it seemed to be working fine, no backfiring and accelerating properlly?

So, any ideas as what caused this? (perhaps just getting rid of leftover carb cleaner or stuff i cleaned petrol tank with?)

Thanks

[foobar]

maybe some crud left in your main or mid jet from the cleaning. sounds like it got blown out when it started running right again.

[Jace009gs]

yea either the petcock got cloged then uncloged, something blocked your fuel filter or the jets had some floaty leftovers....Or you had varnish for gas/peterol as you say