plug vibration

Discussion in '2-Stroke Engines' started by Cordogg, Aug 27, 2008.

  1. Cordogg

    Cordogg New Member

    Because of the vibrations my spark plug actually came out. Does anyone recommend putting loctite on the plug threads?

  2. stude13

    stude13 Active Member

    i would say no. and very unusual. was it tightened properly. never pull a plug from a hot aluminum head.
  3. spad4me

    spad4me Member

    When your engine is cold apply anti-seize compound to the threads of a properly gapped .017 to .028 spark plug and tighten finger tight.
    Then tighten 1/8 to 1/4 turn with a wrench.

    Of course you could just hammer the thing in tight too.
  4. Cordogg

    Cordogg New Member

    it was tightened very throughly beforehand. what can the danger be in pulling a plug from a hot aluminum head? thanks for the tips,

  5. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    The aluminum it is threaded into is fairly soft and easily damaged or
    cross threaded.
    Is the sparkplug crush washer in good condition or is it flattened too much?

    did the plug coming out do any damage to the threads?
    Hot gases would be escaping through the threads.

    If you screw up the thread you will have to heli coil it to save the head.

    Get a new spark plug and crush washer and the anti seize compound
    is recommended.
  6. Cordogg

    Cordogg New Member

    thanks guys. any ideas on an exhaust gasket - buy a new one from a MB parts dealer, use high temp rtv, or does it make a difference without one?
  7. jmccrury

    jmccrury Member

    I would say that the exhaust gasket is necessary. If not, hot oil/fuel will leak out around the connection ruining your pants or burning your leg if wearing shorts.

    I just bought a roll of gasket material from tractor supply for $4 and used gasket sealant with it. They were out of the thicker gasket material so I just made two and stuck them together. So far no leaks. I think the high temp rtv might have been easier though. At least I have plenty of material for gaskets now.