400ex cutting out in water

[bluegrass89]

when i get my 400 in water it starts cutting out and backfiring ..but when i get out of the water and take off it clears up..it seems to be something is getting wet... but have looked and can not find what it is..any help would be greatly appreciated..

[450Rchaser]

spark plug is getting wet or your sucking water in your airbox somehow.

[bluegrass89]

do you think it would be the plug.. i can get in like 8 or 10 inches of water and if it splashes it starts cutting out.. i bought this fourwheeler used and i noticed the other day that there was a hole to the left of the drain screw on the float bowl it looked like it had threads in it..is there supposed to be a screw there? could the be causing the problem?

[450Rchaser]

well if the hole went all the way thru wouldnt it leak gas. pull on your plug wire and see if its loose. does it have the rubber nipple for the airbox on it.

[bluegrass89]

yes if you talking about the one under the airbox..but it is not getting water in it ...ill check the plug...is there something i can put on the plug to keep it from getting wet?

[450Rchaser]

if the spark plug boot is on there good a splash of water shouldnt cause that

[John451]

Could be plug, or loose cdi connection, poor ground connnection.

[450Rchaser]

Water would not affect a poor ground connection. The water will conduct electricity.

[honda300EXtreme]

heres my 2 cents

carb vent hose, when the vent tube gets submerged it creats a vaccum within the carb starving the motor for fuel (cutting out and backfiring)

to solve this cut hose shorter or get a plastic T splitter and run 2 more hoses at different lengths, that way the carb always has a vent

[m36indiana]

mine did the same thing, it was sucking up water through the bottom of the air box, i closed the drain hole off and no more problems

[bluegrass89]

but i have that rubber nipple on the bottom...can it get past that?

[John451]

Originally posted by 450Rchaser
Water would not affect a poor ground connection. The water will conduct electricity.

If his ignition is running off the battery and its grounded then if the frame touches water the voltage would decrease alot and it would sputter down to nothing. Either that or it could be shorting something out... getting in te cdi plug and connecting the wrong wires at the wrong time blah blahhh

[86 Quad R]

i've had experiences where the plug boot seemed to be fine but would allow a slight bleeding of the spark when water splashed on it.

take the quad and place it in a foot of water while running and splash water on and around that area. or until you find the problem :cool:

[FMX40089]

Originally posted by honda300EXtreme
heres my 2 cents

carb vent hose, when the vent tube gets submerged it creats a vaccum within the carb starving the motor for fuel (cutting out and backfiring)

to solve this cut hose shorter or get a plastic T splitter and run 2 more hoses at different lengths, that way the carb always has a vent

I think this guy has got it figured out. You said that the hole was just open right? Put a hose on it if there isn't one, and then route it some where that isn't going to let water in. And I'm talking about the hole on the carburetor not the airbox.

[Quad Dude]

mine used to do that too. and never thought much of it cuz i hardly ever hit water but. where ur carb connects to the head some of those older boots were made out of rubber bonded to aluminum and like mine threw the years the rubber part breaks away from the aluminum and thats where water got in. mine ran just fine as long as it was dry till it really came loose and then it ran really lean on me and i found out wat i was and got a new one and that one was made out of hard plastic and rubber. i only had a problem with water if it was splashing i could drive slow thru water over the tires and i was fine.

[sodbuster]

If you have not corrected the problem yet try taking the connections underneath the front hood apart. Clean them out with brake or carb cleaner. Blow out with compressed air. Pack with dielectric grease and reconnect. Go find a water hole and check it out.