head gaskets?

Discussion in '2-Stroke Engines' started by thuginfc, Nov 24, 2009.

  1. thuginfc

    thuginfc Member

    i have a pk80 slant head motor currently having carb issues but slowly working it out i was wondering about the head gaskets on this thing it seems it has 2 of them

    could i remove one of the head gaskets and then just retorque the head down or would i need to buy a new gasket?

    i was wanting to increase compression to get more low end grunt

    does anyone know how much this would increase compression?

    any noticable gains from doing this?

  2. Dilly Bar Rob

    Dilly Bar Rob Member

    Yes, you can take one out and just re-torque the head after.

    You should get a new gasket though (cheap enough...) or at least "anneal" the old one before re-use. I actually cheated & just took the one gasket out & put some "aviation formagasket" on the other one...no leaks or other problems, but "no warranty" on that solution.

    Don't know how much it will raise compression, you will notice some gain though. In the end I reverted to 2 headgaskets again - I don't weigh a whole lot and the bike was harder to start for me with the raised compression.

    Hawaii_Ed and other members have also done this successfully. Seems that all pk80's come with the 2 gaskets from the factory.
  3. thuginfc

    thuginfc Member

    "anneal"-not positive what that means but i think soething along the lines of heating it up before torque it back down

    i was thinking leaving the bottom one for it has already formed to the jug and the top of it should still be flat since its butted agianst another gasket

    also how mush of a gain was it? was it real noticable?
  4. Al.Fisherman

    Al.Fisherman Active Member

    What I do is remove one gasket (200# and no starting problems) use copper coat and mill the head down (lay on flat glass or window and use 320 grit, only take off what is needed to have a shiny surface). Reinstall head and torque to between 120-204 (I use 150) inch pounds all after I replace cylinder studs with grade 5 (metric grade 8.8) and self locking nuts. Copper coat helps on these engines due to the fact that they don't make them to the specs that good modern engines are. My son weighs 135# and slides the tire while trying to start the bike...we might have to add a gasket when the engine is transfered from the 26" to the 20" chopper..