400ex Gasket problem

[Nate105]

Hey guys

My wife has a 2001 400ex with some mods but the problem I'm having is the head gasket keeps leaking. I put one head gasket in about three months ago and we just put in a new one 4 days ago and we went for a ride yesterday and its bad again. when you hit the gas you can see the oil blow out the side in the same spot as the first time. do you guys have any idea what could be wrong?

[DragonGunner]

You will have to take it apart again, have the head inspected for warpage and getting it plained. Then if you are running high compression might as well get some GT Thunder heavy duty studs put in while your at it.

When torquing the head you are doing it like the manual says right?

[Nate105]

she is running a 11:1 piston and I torque them down to 33 ft-lbs. Now how does the motor get that hot to warp? I have never heard of that on a wheeler. Is there a pattern to torgue them down?

[DragonGunner]

33lbs. is correct but you want to do a criss cross pattern in about 3 steps....I tourgue to 13, then criss cross and come back and torque to 23 then start over an torgue to 33. I have had my head warp, they do get hot being air cooled, plus the stock studs will heat and stretch enough so that there is a tug of war and helps in the warping.

[Atvers]

I agree you need to take it apart again and make sure to clean the both head and block surface free from any particles. Another thing inspect the surface may be there is some damage on it that is why its leaking.