buring oil on startup?

[jb400exxx]

i had just noticed today that my 400ex smokes a little bit at start up when the engine is cold. i was wondering if this is normal and i just didn't notice it till now, or is it the first sign of piston ring wear. am i going to have to rebuild my motor soon, or is it ok?

[jb400exxx]

my dad thinks my rings are on their way to being bad. i kinda hope he's right. i want an excuse to do a full rebuild with high comp, and new cam, clutch..... NEED MORE POWER!!!

valve seals usually, my 400 does it , but ive seen alot of em do it, has to do with the oil breaking down too

[jb400exxx]

so how big of a deal is that. how much should all new valve seals cost. i'm guessing i should do all 4 when i do my rebuild, right? should i get stock or do other companies mke them?

[redrider ex]

:D

[jb400exxx]

so i'ts not my rings??? valve seals are pretty cheap right?

[jb400exxx]

oh, and is it an easy to change the valve seals. would it really be the valve seals even if it only smokes when the engine is cold. it only smokes for about a minute or 2. once it's warm it's fine.

[redrider ex]

and there not to much but im not sure off the price

[jb400exxx]

is it ok to ride it like it is for a few months or should i really fix it A.S.A.P. ? is it gonna hurt anything? would it be ok to wait until december or january when i do my rebuild to replace the seals?

[redrider ex]

the valve seals get worn a bit and when the motor cools down it lets oil leak between the valve and the valve guide and then drips down on the piston . And when the motor gets hot it exspands the valve guide and seals off mine does it to.

[jb400exxx]

alright, thanks, i'll take care of it when i do the rebuild this winter.