reason my 400ex was smoking

[Dalex]

the reason my 400ex was smoking, I bought it from a guy who let it set for a year, the picture is not real good but if you look close you can see the oil ring has collapsed and was allowing the oil to blow by.

http://img.photobucket.com/albums/v624/dalex/piston.jpg

[ny300exrider]

what was your smoke like, consistent smoking or once and awhile puffs??

[Dalex]

heavy under a load, and high revs, didn't smoke at idle

[2001-400ex'er]

I have that same problem of smoking when revving it high or once it gets hot I can smell it. At least I have a good idea of what it is now..

[dirtmomma]

Yeah our 400 does the same thing :( but not bad for being a 2000!! Time for a new piston/rings :D

[ny300exrider]

yea that could be my problem, mine will puff some smoke once and awhile only when riddin in high rpms for awhile. how much was it to fix and did you do ti yourself?

[Dannys400ex]

mine did the same thing, so i pulled it apart and now have a 440.

[ny300exrider]

im not going to do anything with mine for awhile, the smoke is very minimum and only does it occasionaly,i just rode it and didnt see one puff and rode for 4 hours in the snow a few weeks ago and always looked back to see if i could notice anything and didnt see anything. i think it does it more in warmer weather, oh well it doesnt have any effect on power so its not worth ripping it apart, dont want a big bore either

[Dannys400ex]

i probably wouldnt have went went the big bore either if i would have known thats what it was, but i ordered it before i tore it down, but now that i have the 440, damn this thing is mean!!!!!

lol