My nsr 125 kept cutting out in the rain, i think its because water was being sprayed up from the front tyre onto the spark plug/ht lead, havn't found a perfect cure for it but a spray of wd-40 on all and surrouding areas before i set off usually does the trick.
Obviously this would only be the cure if it cuts out when its raining / when the roads are wet. What happens when it cuts out, do you just lose the spark? ie. if you try revving it more after its cut out can you hear it pushing fuel in but just no ignition?
if so this could be the reason...
goldielocks, March 2008