a real head scratcher?

[2004exrider]

Im pretty stumped. Yesterday i was riding some trails and in a part you have to cross a river to get to some hills. Well i start crossing it and the engine starts popping like crazy the whole way across. Its never done this before? At first i thought that water may have started going in my intake/exhaust but as i rode thru it wasnt even deep enough to. Every time i crossed it that day it would do it! Has this ever happened to anyone, and if so how did you solve it. Thanks in advance for your help, this forum always comes through for me:D

Jimmy

[1fst400]

my guess is electrical.. If I was you I would take apart the conectinos going to the cdi box and fill em with electrical greese.

[GPracer2500]

Electrical was the first thing that popped into my head--but I couldn't quite think through precisely what could have been happening. Maybe water was splashing up somewhere and causing a momentary short??

The second thing that popped into my head concernes the vent lines for the carb. If they were submerged then I wonder if the carb was having trouble filling the float bowl properly [shrug]. Seems like I've heard of a similar phenomenon happening before but I don't remember the details.

Next time you go through the crossing, try fishing your vent lines out and routing them above the water line. Maybe??

Good luck.

[1fst400]

check the electrical issue by starting it and soaking the wires with a hose. if it has issues then its got a chafed wire or sumthin

[bigbearkid4x4]

make sure your spark plug wire is fully snapped on the spark plug

[2004exrider]

Thanks guys:) , i started it up today and tired a few things. I got the hose out and sprayed the electrical connections and revved it up it ran fine, checked all the connections, vacuum lines are fine:confused: . I'm pretty stumped, ill probably run down to the river sometime tonite and cross it again and see if it still pops. Wish me luck! lol.

Jimmy

[boricua]

you know baja bugs shared a very similar problem. it turned out, the water splashed onto the hot engine would steam and vaporize. that steam would find its way up into the spark plug boot, the part that connects to the spark plug, and create a short or intermitten spark, which in turn caused it to backfire. both machines are air cooled. it may be that in your case, or maybe the steam found its water into another electrical component and shorted it out......????? could be a reason why you werent able to find it by just hosing down the quad while idleing...
2 pennies.