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View Full Version : another head gasket prob..


below100hz
05-13-2008, 09:56 PM
i know, just what you all wanna hear about.... ive searched but looking for more info before i go with hd studs

i havent had a head gasket last me more than a month with my 426 and 11:1

the last one i put on i made sure to torque it to spec and it actually leaked the second i started it, tightened it more and it stil leaks.
its getting pretty bad now, you know, when you can hear the compression spraying out :rolleyes:

all the head gaskets ive used have seemed to be for the stock size bore, even the one that came in the kit, could that be it? im about to order a cometic big bore gasket kit and im wondering if theres something else i should try before studs or what, i dont wanna blow a 4th head gasket :mad:
one more thing i recently thought of is that the bottom most engine mounting bolt has been missing since i got my quad and whenever i put the top end back together i have to pry the motor to get the top bolt to line up... i know :eek2:
but could that cause my ****tt to tweak and blow gaskets?

oh yea and i had been running 93 before but now i run a mix of race gas
Reticle
05-13-2008, 11:26 PM
I'm no master mechanic, but it sounds like a warped head to me. Maybe when you pull it back apart have a machine shop check it out for straightness.
Ruby Soho
05-14-2008, 06:46 AM
by now, your head is most likely warped

bring it to a machine shop and have it decked.

put in the GT thunder HD studs, it will solve your problem.
below100hz
05-14-2008, 04:01 PM
alright ill have them check it out

do i really need to get a big bore head gasket? it is gonna cost me twice as much as a stock bore one
below100hz
05-19-2008, 02:29 PM
BTT

do i have to get the big bore specific head gasket for a 426?
sc400ex_rider
05-27-2008, 11:01 AM
yes the stock gasket and aftermarket kits are clearly noted as 86MM this is for a 85MM piston. your piston is 88MM so i would get the 88MM gasket. all of the ex motors tend to settle in the frame, if you adjust the vavles with the bolt out then pry it in they will be out of spec. i elongated my holes to fit the bolt then adjust the valves and they are pretty quiet.