White Smoke!!!!

[red03400]

i was riding w/ my friends and white smoke poored outa the exhaust then stoped....i didnt think anything off it untill i lost power and it kept blowin white smoke out at high rpms....i got home and took the spark plug out to see if there was any oil/junk on it....it was dry as a bone....and now i have no idea what the problem is....did i blow my rings?...or is it something to do w/ the valves....thanks

[Chino886]

Originally posted by red03400
i was riding w/ my friends and white smoke poored outa the exhaust then stoped....i didnt think anything off it untill i lost power and it kept blowin white smoke out at high rpms....i got home and took the spark plug out to see if there was any oil/junk on it....it was dry as a bone....and now i have no idea what the problem is....did i blow my rings?...or is it something to do w/ the valves....thanks

did you ride through water?

[rooster300ex]

What did it smell like. Thats how u can tell if its oil or gas or something else. If its oil burning at high rpms its prolly the rings. make sure u check your air boot and all that stuff for leaks, mine all of a sudden started smoking and then i got to lookin my air booth wasn't even on mine carb, so it sucked dirt in it and messed the rings up.

[red03400]

no i was just riding in a field and it only blows smoke when its warm/hot

[red03400]

yea ille check the boot now...and it smells like a mixture of oil and fuel...but it definatly smells..i can smell w/e ime smeelin from 5 yards away

[Chino886]

Originally posted by red03400
yea ille check the boot now...and it smells like a mixture of oil and fuel...but it definatly smells..i can smell w/e ime smeelin from 5 yards away

I would say check your rings, sounds like a bad deal.

[red03400]

yea the boots attached

[red03400]

yea ime gunna do a compression test and all that shiz lil bit..the damn things still piping hot

[red03400]

could it have overheated?

[Chino886]

Originally posted by red03400
could it have overheated?

How long did you ride? I was in OK at little sahara and I rode hard for at least 2 hours and mine did not overheat and it was over 90 degrees the whole time. I am also running advanced timing, high comp piston, cam, and aggressive cdi.

[red03400]

i was riding from 3- 3 1/2 hours wide open in fields

[Chino886]

Originally posted by red03400
i was riding from 3- 3 1/2 hours wide open in fields

I am guessing that you did not overheat, I see that you have scoops and if you were wide open the scoops would have helped with air flow.

[red03400]

yea....it just really bugs the hell outa me cuz its an 03 and i dont beat on it...unless ime at the track but i still dont really beat on it there eather...the dealer that i got it from ***ed everything up from the begining.....they gave it to me w/ no float in the carb and the needle was loose.....so idk if they messed it up from the factory or whats goin on

[Chino886]

Originally posted by red03400
yea....it just really bugs the hell outa me cuz its an 03 and i dont beat on it...unless ime at the track but i still dont really beat on it there eather...the dealer that i got it from ***ed everything up from the begining.....they gave it to me w/ no float in the carb and the needle was loose.....so idk if they messed it up from the factory or whats goin on

did you buy it used or brand new? if it was brand new and you got it from a honda dealer, I would call Honda corp and file a complaint against that dealer.

[red03400]

yea it was new...got it from dutchess wreck....i gave it back and they fixed it for free but now its smoking...not ever 3 years old

[Chino886]

Originally posted by red03400
yea it was new...got it from dutchess wreck....i gave it back and they fixed it for free but now its smoking...not ever 3 years old

Have you ever rebuilt it? If not, you should rebuild and put a new piston and cam in, it will be a different bike when you are done. It will only cost you about $300. You won't be disappointed.

[red03400]

no rebuild but..i was thikin bought a 416 kit...from powroll for about 270..cuz i got a friend that can bore it and i can do the rest...but ime def doin this if its the rings and or the cylinder walls r damaged

[Chino886]

Originally posted by red03400
no rebuild but..i was thikin bought a 416 kit...from powroll for about 270..cuz i got a friend that can bore it and i can do the rest...but ime def doin this if its the rings and or the cylinder walls r damaged

Good luck, I had fun with my rebuild. I would also suggest a Hinson clutch basket while you are in there and a 02 crf 450 cam chain.

[red03400]

yea thanks

[quadmad123]

try putting oil in the petrol mix.....you have probally blown it...

[kfxwizzard400]

Originally posted by red03400
i was riding w/ my friends and white smoke poored outa the exhaust then stoped....i didnt think anything off it untill i lost power and it kept blowin white smoke out at high rpms....i got home and took the spark plug out to see if there was any oil/junk on it....it was dry as a bone....and now i have no idea what the problem is....did i blow my rings?...or is it something to do w/ the valves....thanks crack the cylender open and see if the piston skirt on the intake side is still there. mine did the same thing and it was the piston that cracked in half. also it being an 03 doesnt mean anything. if u rode it alot for them 2 years and didnt replace the rings or piston id say u brew it up. Sucks though i have when it happends

[BLACKeR]

the first thing i would check is your compression. you can get a compression tester for $20-40 at an auto parts store. there good to have. if you compression checks out you should not have to re-build. i dont know what the compression for a 400ex is supposed to be, but im sure someone else can give you the numbers. typically white smoke is from water evaporating. in a liquid cooled engine if you see white smoke it usually means you have blown a head gasket and are sucking in coolent and its evaporating. on an air cooled bike like the EX i dont exactly know why you would be gettign white smoke. but it sounds like you might be overheating. that would cause you to lose power and you said it only happens when you have been riding for a while and the bike heats up. it could just be that your jetting is off. if you compression checks out and everythign looks normal try going up one on your main jet and see if that makes a difference

[keihin fcr]

Dude first white smoke can be caused by coolant,transmission fluid and moisture in the exhaust. 2 of the 3 are excluded sounds like moisture. 400ex's are air cooled

[keihin fcr]

My brother put kerosene in a gas can and didnt label it and i put it in a pocket bike with my oil mix. It would idle but nothing past mid throttle. It would pour out white smoke. Drain your gas tank and put some new gas in it. Sounds dumb but it happened. It actually ran:) I hope this is your problem.

[rockman]

My brother put kerosene in a gas can and didnt label it and i put it in a pocket bike with my oil mix. It would idle but nothing past mid throttle. It would pour out white smoke. Drain your gas tank and put some new gas in it. Sounds dumb but it happened. It actually ran I hope this is your problem.

Ya i work at a yamaha dealership and we had a guy bring in a 5 week old r6 that he had filled with diesel. needless to say it smoked like a ****** for a while. i'd say smell the gas first.

[flyin#5]

im calling rings.... ive rebuilt 3 4 strokes (one 400ex) that were burning oil this year, sounds like the same thing. when did you change the oil last?

[Trevor]

With cars white smoke usualy is coolent. Oil is more of a blue and too much fuel is black. If it's liquid cooled I would say head gasket.