blowing headgasket

[btyoe]

hey i was just wondering if anyone has any idea why we keep blowing the head gasket. its a je12.5:1 416 we have had it apart 2 times now and cant figure it out

[400ex124]

i had same problem with my 440.... i took it to honda, they said that the threads that the head bolts went into were stripped. just a suggestion take it there before you end up spending alot of money on it. none of the BEST mechanics around hear could fix it, and i ended up learning it was best to take it to honda when you cant figuer out wats wrong with it the hard way.

[PismoLocal]

That is the most common problem for 400ex motors that run higher than stock comp ratio's. It is only around $60 to fix it. All you have to do is buy a heavy duty head stud kit and install it. It will keep your head tight on the cylinder and stop you from blowing head gaskets. While your in there I suggest you replace your stock timing chain with a crf timing chain, they are only $27 and won't stretch like the weak stockers do.

[btyoe]

where do you get the hd stud kit

[RiderTRX400ex]

gt thunder

[AznxXxStunNa]

Originally posted by PismoLocal
While your in there I suggest you replace your stock timing chain with a crf timing chain, they are only $27 and won't stretch like the weak stockers do.

which crf (year/cc) are you talking about? Are you talkin about a oem or aftermarket cam chain?

[PismoLocal]

Aftermarket cam chains that you buy are just CRF450 cam chains. Usually people sell them for any where from $50-$100. You can buy a crf cam chain for $27 from honda and it is twice as thick as your stocker. Stock cam chains have been known to stretch when you bore out your motor and move to a higher compression piston. Go to service honda and type in the part number I'm providing. Part #: 14401-MEB-671

[AznxXxStunNa]

koo man thanks.