had the same thing happen to me the first time i got caught in rain. after the bike dried out i sprayed all the electrical connections i could find with electrical spray grease, no probs since including the poxy thunder storm i got caught by tonight:roll
I sometimes have this problem. Somtime afterwashing I find that there is water under the fuel cap Usually resting on the platic lip. I try and soak up the water with a cloth.
It could be that water is getting into the fuel system and causing problems with the fuel injection.
I had that the drain pipe is blocked take tank off and take the drain out mine was so full of **** i had to drill the drain nut out it screws in bottom of tank and all the **** builds up and blocks it just undo it and drill it out its about 4mm hole and the water at the top of the tank will drain away. drain the tank out as the water will not help hope this helps give it all good spray with wd40 or sim:thumbup
This is probably caused by the thermistor in your airduct (clutch lever side) It will throw an efi code when there is water lying around it or the connections are corroded.
If you ride in all weathers then you need to go through the bikes electrical connectors and clean them up with electrical terminal cleaner then fill the plugs with Dow Cornings DC4 electrical grease.
Do a search on Google or this forum for where to buy, pretty sure it's available on Flea Bay too.