400 boggin out, cutting out..goin thru water etc..

[2001400exrider]

ok, whenever i go through some water on my quad it bogs right out, when i hit throttle there is nothing, no revs or anything and it sputters and chugs for a bit then is fine agian....kinda same thing happens when i pull wheelies and go over really roush terrain...i dont think its my jetting...Im pretty sure its an electrial prob? maby spark plug wire? anyone else have similar prob? its really annoying...gotta be some connection...Because eeven one day when i was goin over some real rough stuff, big whoops and rocks and stuff it started happening and i barly made it home sputters and chuggin and boggin so bad..

also, my jetting is...
-175 main(i kno thats perfect...)
- needle clip second postion from bottom. (thats perfect)
- fuel screw 3.5 turns out..(was 2.5 but opend it up for more bottom end..)

Iam EXTREMLY happy with my gains from the exhaust, air filter but this problem is extremly annoying...i need help...

[duke416ex]

You just have a full exhaust and a filter and are running a 175 main, dange. :eek2: Sounds big but if its good, then it's good, of coarse you are in a little different climate than me.

My 400 has the same problem, but mainly just in water and realy rough ground. I am kinda thinking maybe it is something in the connections of the cdi or ignition, but am unsure, if you find out be sure to post it so I can look at it on my bike.

You probly have a hose hanging low n when it hits the water it bogs

My old quad n a friend's had the same problem maybe check it out

[2004exrider]

imo, it sounds like you are a little on the rich side. it runs fine when you are driving normal but when its under a good load its probly not able to burn all the fuel thats coming in (happened to me). check your spark plug to see how it looks, that should tell you everything. try taking off the airbox lid and drive it kinda hard and see if it does it then (avoid going thru water though). might also wanna check that the main jet didnt fall out, other than that it doesnt really sound like an electrical prob to me? if you find out please let us no.:)

Jimmy

[2001400exrider]

but it bogs so bad, when u hit thorttle there is NO response liek no spark, the BAM and WOAH its it will like chug fora few mins after water crossing and then its ok....

[47501exracer]

I had the same problem but mine was caused by the K&Suck air filter that I was running. I took the K&Suck off and put on a foam filter and haven't had problems since. I see you have a UNI, maybe you need to clean it well and oil it? Also cut a hole in the airbox drip tube so water and mud can flow out it.

[2004exrider]

i wouldnt ruin the tube, why not just take it off. ya how long has it been since you cleaned your air filter? did you check to see if water is getting in your airbox? Might also wanna check that theres no loose connections between the intake manifold, air hose, or inbetween any part of the carb creating an air leak.

Jimmy

[Woodsracer400ex]

Having same problem with my 400ex, I'm replacing the spark plug wire cap and coil. I will find out the next water crossing if it works.

[2001400exrider]

yea this is wat i think it is too...........let me kno if that fixes the prob...

[400exstud]

READ THIS!!! I am 100% positive that your jetting is too rich. Your setup is the same as mine and I went through the same crap you have. Let me guess you got your jetting tip from the HMF site?

I take it that you are running with the airbox lid on? If you're not the only part of my solution to your problem that should change will be the requirement of a larger main jet.

I started out with a 180 (as HMF suggested) and it was sooo bad that I ended up going from a 172, 168, and am now at a 160. You need to be around this area. If I were to rip my carb apart again I would go with a 158 because I am still a bit rich but it is ok.

Then you need to move your needle back to its stock position because that too is a bit too rich.

To test and see if your quad is too rich take the airbox lid off. If it runs better than it is to rich. If it runs worse than you are too lean and with your problem this will not be the case.

I would be willing to bet anyone on this site all of my money that this is your problem and my proposed solution will make it better.

Let me know how it goes.

[2001400exrider]

man i started at 162 main and it was WAAAYY to LEAN pure white plug on plug check...then went to 170...did a check, plug was still white with a little grey, went to a 175 and it was perfect tan brown...so i kno my main is correct, and as for the needle clip, its second position from the bottom and that controls 1/4-3/4 throttle and my mid range RIPS. only other thing is the pilot and i got the screw 3.5 turns out..which seems fine when u hear about everyone sayin goto a 42 pilot which is wayyyyy fatter then 3.5 turns out on the stock pilot..

[2004exrider]

have you done a spark check on it? maybe check all your connections and clean them off. they could be shortin out, maybe rusty or really dirty?

Jimmy

[2k426micheal]

check the part between the carb and cylinder. mine was crack where in metal and rubber are made together.it was sucking in water there and it would spit and sputter

[400exstud]

That seems wierd that you would need to run that kind of jetting because I have seen people on hear that are running as lean as a 152 or even stock for the same setup that we have.:eek2:

[2001400exrider]

depends on elavtions and climates.....

[400exstud]

Yeah I know it depends.........but not THAT much.