KX100 Keeps blowing head gaskets

[Rikster]

KX100 Keeps blowing head gaskets. Pweeese help :s

My KX100 keeps blowing its head gaskets whenever i take it for a ride. It will run good for a while but then water starts spraying out of the presure relief valve on the radiator and the hoses feel very preasurised.

I then usually let it cool down for a good hour then take the cylinder head off and the head gasket is all crippled and feels... crispy. Is this because i've done the head bolts too tight or too loose? or is it the heat or something? Thankyuu :laugh:

 

[Patman]

Warped head or cylinder mating surface? Fasteners too tight? A few options. A factory service manual would help you do the job correctly (i.e. proper torque, etc...)

 

[gary2010]

i dont own a torque rench so i normally just tighten my cylinder down as much as i can lol and it never has blew a gaskit. my old dtr125 i had blew the piston a scared the bore so i went for a rebore at the bike shops they were sayin it will probly happen again if i didnt get the head and cylinder machined once i got it machined it was perfect its still going to this day. all they done was make the cylinder and head have a perfect fit they must of grinded a little piece off to make the surface perfectly flat again. this might help but it might not

 

[akagalford]

You may want to have a look at your water pump gear. On the KX100 I found the main pump drive gear is plastic and the gear can be chewed up which stops the water from flowing. If the head over heats it could cause it to warp and spring a leak.

 

[Rikster]

Turns out there was a small chip in the cylinder head where it mates with the gasket. This let the compression get through into the cooling system and thats why water was spraying out the pressure valve. New head fixed the problem. Thanks Patman.