Hey guys, I bought an old Honda today to ride around Thailand with. The previous owner had it rewired recently, however a few days ago during the Thai New Year (a water festival), the bike was hosed down a few times and now the electrical system stopped working. All I can tell at this point is that all of the bulbs blew out. I have no tools here so I can't check volts/amps easily. The bike is kick start only so I can start it fine but I would like to be able to ride the bike at night. Any ideas what I should replace first?
I'll post a picture of the bike in a few minutes.
Take all the electrical connections apart and clean the grounds.
Sounds like a good start, thanks Woody!
water could have got into the stator inside the engine case. There's usually a cover that comes off with a couple phillips screws.
That's a bit strange. The should be a 6v battery (pretty sure), but that alone would not pop the lights. It think only the stator could do that. Generated voltage on those bikes is mostly controlled by the battery absorbing extra. There should be a rectifier (it's a tiny box) in the power stream to turn the AC into DC (simply cuts off half the wave) and that should cut down the voltage also. I am not sure those rectifiers every go wrong though but something to be aware of.
The only test I can think of is putting in a test bulb, turning on the bike (not starting) and see how the bulb does, it should do fine. Then start the bike and see if it blows. The headlight should be powered from the stator I believe, the only real use for the battery is to power the tail light when the motor is off. But, if the stator is wonky, you could disconnect it and run the tail light (and others) off the battery. Of course, if the stator is wonky your headlight may blow....
...so, bet bet is likely to try and clean out the stator and it's wires as noted (as mentioned above). Not sure that's helpful, but it's some more info. A wiring diagram can likely be found online.
Thailand is a great source for old Honda bike parts BTW.
That sounds as if the charging system is going 'full field'. The typical charging system is a closed loop; the stator generates power that's fed to the battery. The rectifier and regulator sense battery voltage and turn the stator field on or off as needed to keep the voltage within specs. If there's no connection to the battery or something is grounding out against the frame then the stator runs wide open all the time, the rectifier and regulator don't turn the field off. Since it started after the bike was washed that tells me something got water in it, most likely the rectifier/regulator connector. All it takes is a little wet corrosion to provide those electrons with an unwanted path to ground. I'd suggest Googling the model of the bike (CB, CL, XL 125 etc) and look for the position of the regulator and/or rectifier. Clean those connections well with contact cleaner then reassemble and try it again.
EDIT: If the bike was 'recently rewired' that's the very first place I'd look. The headlight shell is where most motorcycles gather all the wiring together, I'd pop the headlight reflector assembly out and start checking connections there. It looks like Honda had pretty much quit with rectifiers by 1983 (at least here in the Great Satan) so I'd suggest you look for the regulator, which will be a small plain box with a wiring pigtail (assuming it's like a US model). It will probably be mounted on the frame downtube behind the engine or possibly on the battery box under the seat.
Post some pics of Thailand as well, and have fun! Don't go all Clarkson over there, though. 
