COOLANT ISSUES?????

[Drtybrd21]

alright im new to this so i need all the help i can get....i just had the top end of my 94 kx125 sleeved and then i dropped the piston in and i started to break it in (few hours, tank of fuel) until everything just shut down and wouldnt start....i drained the oil and it was pink(i run gear saver which is dark red) also rad was empty so i filled it up and started kicking... next thing i know coolant was shooting out of my silencer.....anyway i got home changed out all my gaskets and also the water pump seal...i solved the coolant in the case issue but my bike will run for a while then the rad seems like it builds up pressure then will just go and fill my pipe up with coolant....i had checked the head when i ripped it apart and i didnt see anything so im wondering if someone has an idea of whats going on....please help

[KXcam22]

I would suggest that the sleeve is not mating to the head properly.  Once the cooling system builds up to normal pressure the head gasket starts leaking coolant into the cylinder top-end, hence the coolant in the pipe. To fix this, you need to lap your cylinder head to the cylinder.  This is easily done by putting valve grinding compound on the mating surfaces and twisting a number of 1/4 turns of the head on the cylinder.  Keep this up until the contact surface shows an even gray color.  You have probably figured out that you need to pull the head studs out of the cylinder to do this.  I have used this to prep engines for NO headgasket, so it does a good job at mating the surfaces.  Hope this helps. Cam.

[BDI]

I know when they put in a sleeve they will deck the cylinder. When a cylinder and head have been together for a long time they get to be like a mated set and if you machine the cylinder they will not fit together right. The result is your motor will not hold a head gasket until you machine the head or lap it so that it is just as flat as the cylinder deck. I have also been told by an old guy that did this stuff for ever that when you deck a sleeved cylinder that you should leave the iron sleeve up .002 so that it pinches the gasket better and he rattled off some stuff about heat expansion too.