why does my motorcycle cut out in the rain

basically when it rains and im riding at like 40mph for say 3 miles the bike will start to jump about and has the effect of it running out of fuel . the only mod it has on it is a sports exhaust , if it was the exhaust causing the problem it would do it all the time and not just in the rain

whats people's thoughts on this i'm guessing its some kind of electrical fault , but dont have a clue where to start or what to do about it

any help is much appreciated

thanks

 

I can only think of one thing initially if you say it only happens in the rain and that was on Chinese motorbikes as opposed to scooters. That was down to the fact that some of them used metal covered plug caps, because they looked more bling. The rain water could short out the HT voltage to the cylinder rather then let it spark the plug. On scooters this plug is typically within a plastic shroud in side the body and therefore not get wet.
Of course you could be talking about your bike in the Avatar

But check the plug cap is good, that it has the rubber seal that fits around the plug body to help keep water out, that it is a plastic type and not metal.

Rain water will not short out 12 Volt systems but will corrode wires after even a short period of time leading to intermittent breaks etc.

Adrian

 

another one and most probabale is that there is water getting in through your air filter

 

the bike is a 2009 honda cbr 125,,going to look over it and probs replace the spark plug for good measure n see how that goes first because visually looking theres only one split rubber item and its the earth to the starter motor but the starter works fine

 

mine did that in the rain with a standard air box..worse when I did an open filter...also had the cap problem too...the two faults had me changing the coil,carb,plug and finally the cap..before I found what it was..THE CAP...got a new pipe too...well loud..chinese bike mind but water is water..

 

probably water getting sucked in, did you change the whole exhaust or just the tail pipe? if you changed the whole exhaust what did you do with the PAIRS tubings and stuff (the emissions stuff that goes to the airbox) that could be the whole problem

 

there wernt no tubes on the exhaust to take off when i removed the old exhaust

 

the thing that the spark plug connects to the coil ?

 

water is 100% getting in to something somewhere
start with air box and seal the "seal" up with some sillicone
change the cap itself if you can and get one with a rubber boot on it that should stop water getting into those two

that's the spark plug cap
try to get one that look like this with rubber boot on

 

yeah ive orderd one of the caps its the same as the top one so hopefully this will solve it and also going to put a higher heat range plus seen as mines looking a bit pink