My bike cuts out frequently after it gets wet. :x

Any ideas why?

Thanks

Quote from: dnorwooMy bike cuts out frequently after it gets wet...Any ideas why?

We need a little more information here. It is the engine stumbling, yet running, or just stopping and won't start again?

The ground cable from the negative battery post to the chassis is always suspect with water and the "auxillary ground" that is a smaller wire running off the large one is also a suspect. Disconnect and reconnect all the connectors under the body panels and check for dirt-corrosion.

Engine is hard to start when cold and then stumbles past 5000rpm and shuts off if pushed.

Quote from: dnorwooEngine is hard to start when cold and then stumbles past 5000rpm and shuts off if pushed.

All right, better details!  

The stumbling past 5K may be electrical related or not. If your original thought is complete, are you saying it runs fine and exhibits none of these symptoms when dry and only acts this way after being driven in the rain or getting rained on?

If the above is true, again suspect connectors out in the open. What year GS is this? From 89 to 02, most things electrical are the same. 03+ depends on your market (read that as what country you are in).

It may be either spark plug leads/caps or ignition coils or maybe pulse generator coils. It tell you in the book how to test these should be chapter 4 I think.
This happened on my bike and the left spark kept failing on me so I got some pulse generator coils from a breaker which fixed the problem.

Yes it runs great when it has been dry for a day.

Quote from: ukchickenloverIt may be either spark plug leads/caps...I got some pulse generator coils from a breaker which fixed the problem.

Translation: breaker = used parts seller.  In the US, that may be a m/c salvage yard, a dealer with a boneyard (US -> UK translation: junkyard   ), or any other source for a used part.

Sooooo. It runs fine when totally dry? You must have moisture intrusion into a low voltage connector OR as ukchickenlover says a breakdown of the high voltage system. The only high voltage present is the short run from the spark coils to the plugs.

Check the spark plug connections for cleanliness. After a couple of dry days, with the engine cold AND OFF, shoot a small amount of WD-40 over the cable from the coil itself to the spark plug cap and wipe off the excess. You should get all the cable wet and wipe off the excess.  Again, do this with the engine OFF and cold. Allow the carrier several minutes to evaporate. The goal is to eliminate possibilities. Rumor has it that "WD" stands for "Water Displacement". The carrier is flammable, thus the COLD AND OFF requirement.

You could use a silicone spray, but that stuff gets everywhere and is very slippery.

As ukchickenlover brought up, check the connection from the ignition rotor signal coils, right side of the engine under the round cover, all the way to where it connects to the ignitor or wiring harness. The oil pressure switch is also in that cable.

Do you have a service manual? What year bike is this?

Quote from: starwaltRumor has it that "WD" stands for "Water Displacement".

<off_topic>
Check out the official WD-40 history page.  Second paragraph.
</off_topic>

I had the same trouble when I got mine. It turned out to be the way my overflow line was routed. The previous owner had connected the carb vent to the tank overflow. (The other connection under the tank.) When it would rain or get wet, water would drain right into the carbs. It would take quite a while for the problem to go away. Good luck.

A little electrical grease in the wire harness connections will work wonders.