The front spark plug cap can develop a crack because it is long and is often bent when it is removed to get access to the front spark plug. I'd check that first. A crack may be hard to detect. Let the bike idle, get a spray bottle filled with water and see if you can induce a misfire by misting the plug cap and lead.

 

Could be vacuum lock. Check the hoses coming from your tank... if they have water in them your tank can't vent and fuel flow will slow substantially. An easy way to test this is to pop the gas cap when it's happening- if the bike runs with the cap open then this is probably the problem.

 

Two obvious things to check

1) The front cylinder plug cap can fill with water if it it isn't waterproofed (i.e use silicone grease) and then if water does get in and flood the plug if a small drain hole isn't clear.

2) If you have a an aftermarket full belly pan and if this fills with water which the tank breathers etc run down into this can cause a vacuum lock causing fuel starvation.

 

Good plan! DW40 and Duct tape can usually fix everything

 

I ordered the coil, plug cables and plug covers, hopefully that will solve the problem.
I will also check the vaccum lock, hopefully after the new parts i wont have the oppertunity to do that though!

Has anyone heard of a splash gaurd or plate for the front cylinder/plug area thats available?

 

I was having the same problem with my GS650G before I sold it. Started getting worse and it'd do it even when not raining but when ever I rode it hard such as trying to go up the pass at 70mph. I'm guessing it was the tank not venting properly because it'd act like it ran out of fuel, then if you let it sit for a few minutes it'd fire back off and go.

My dad was telling me his old Kawasaki LTD would do the same thing when wet and it was the vent as well. Said it'd get some water in the vent hose which ended right in front of the rear tire. Then the tank wouldn't vent and it'd die. The fix was to put a slit at the top of the tank breather that would allow air in when the water would get in the bottom of the hose.

Check the vent tube for being clear and not being kinked. Also when it's acting up try poping the fuel tank cap open and see if it quits acting up. Just be careful with throttle input and brake changes as the fuel sloshing around could slosh out of the open cap.

 

Well, if it's vacuum lock the new parts won't do you any good. And if it's new parts it wasn't vacuum lock. Just sayin'

 

This was a common problem a while back.....
Check for a low spot in the tank vent line.

The easy was to confirm if it is the vent line is if it happens again, open the gas cap. You will hear the vacuum escape and the bike will fire right back up.

 

Tried clamping all the hoses and reproducing the issue but no luck so seems like the electrical issue is the one.
Kind of glad as I had already spent the money for the new parts ha! Just waiting for the parts to arrive for a final fix I hope. Thanks everyone for the help and tips!