Oil Burn Off at Start-Up

[pr0t0type670]

My 02 400EX is burning oil at start up for about 2 to 3 minutes with a lot of blue smoke. Could it be the rings, compression, head gasket? any ideas


Thanks

[braponmy400ex]

No i dont think so my friend has that same problem and its fine b/c he just rebuild it and put new rings and head gaskets and the com is fine.

start up is usualy the valve guides or motor seals usualy black/white.

if you need rings you see smoke off n on when you drive exspecialy on decell. usualy blue

Originally posted by braponmy400ex
No i dont think so my friend has that same problem and its fine b/c he just rebuild it and put new rings and head gaskets and the com is fine.

my 400ex was rebuilt and was still burning after that. what i found out is the macanic didnt replace the motor seals. if you dont replace the seals you burn oil.

[GPracer2500]

Motor seals? Are you refering to the valve stem seals?

Like not z said, smoking only at startup is usually from bad valve stem seals. When the quad sits for a period of time oil can leak past worn valve stem seals and onto the valves and into combustion chamber. This oil then burns off during the initial moments of running. Unless the valve stem seals are REALLY leaking badly the engine has to sit dormant for some period of time before more oil can leak past them and collect where it shouldn't be.

Bad rings will generally smoke all the time, not just at startup.

[exrider008]

Originally posted by pr0t0type670
My 02 400EX is burning oil at start up for about 2 to 3 minutes with a lot of blue smoke. Could it be the rings, compression, head gasket? any ideas


Thanks

mine is and 02 and it is doing the same thing blue smoke at start up but when i get going it stops. i just did a rebuild and replaced every seal in the motor. is it just because i just did a rebuild? and will it stop?

[mrnate400ex]

i actually had this problem on my 04'. i adjusted my valves since it had never been done, and it solved the problem. i knew they were off, but didn't think it would cause that problem.

[limetimeracerII]

My 400 is doing the same thing. I've been going crazy trying to figure out what it could be. I've replace two valves and the valve seals twice along with inspecting the valve guides. I know its not the valve seals. If they're bad it usually smokes for a couple of seconds mine smokes for a couple minutes but completely stops once the bike warms up. Any help would be nice. Also what what motor seals are you talking about.