engine head leak

Discussion in '2-Stroke Engines' started by Marc Hilton, Oct 5, 2012.

  1. Marc Hilton

    Marc Hilton New Member

    Hey everyone got a slight problem i keep finding black oil stuff on top of my engine i keep cleaning it but keeps coming back, my head gasket looks fine but its coming from the top somewhere.

    What il do is post my Photobucket album to show you the pictures .

    http://s1285.beta.photobucket.com/us...bicycle leak

    Any help is much appreciated

  2. Anton

    Anton Administrator Staff Member

    You may have to check your link it's coming up with page not found...?
  3. Fabian

    Fabian Well-Known Member

    Don't worry about it. Make sure your head stud nuts are tight and just have fun riding your bike.

    I have never had a cylinder had gasket that did not leak. It might look a bit messy but it won't do any harm.
  4. Anton

    Anton Administrator Staff Member

    My older 66cc engine was spitting a fair bit of goo out around the head. I was going to change the gasket but tightening the bolts made it a little better. It's annoying when it spits it onto your jeans and you go into the shops smelling like you've been bathing in 2stroke :ack2:
  5. Fabian

    Fabian Well-Known Member

    I've mentioned this before but been hounded down for my comment: it's better to have black filth and goo on the engine and you, than not having any filth and goo at all - a clean running engine is a sure sign that 2-stroke oil was not added to the fuel; and a clean running engine most likely means you will not make it back home.

    If black filth and goo is spewing out from every gasket and seal, it's a sure sign that the engine will keep on running.
  6. crassius

    crassius Well-Known Member

    There is really no reason to put up with leaks. Clean it and look for where it's coming from.

    On top of the head, it will usually be coming from the spark plug not being tight enough, but could also be from a head stud or leaking down from a bad gas tank stud.

    Leaking at the seam between head & barrel, is a loose head gasket. If taking it to the right torque won't fix it, then check that your head nuts aren't bottoming out (add another washer or 2 if so).

    Leaking at the front of the barrel is a loose muffler or bad exhaust gasket - tighten or replace as needed.
  7. Greg58

    Greg58 Member

    If a new gasket doesn't stop the leak you can true the head and cylinder, I use sandpaper taped to a true flat surface and sand each in a circle till all low spots are gone. This has worked on both of my engines.
  8. adrian101

    adrian101 Member

    I get a lot of oil, dry powder like around the bottom of my exhaust thou my exhaust isn't leaking nor is my head gasket. I run the Banana pipe on my engine so i am guessing it is up spray/oil mist or something!
  9. Fabian

    Fabian Well-Known Member

    Back in the days of WWII and large radial air-cooled engines, there was a saying by mechanics that crossed all language boundaries: if it's not leaking oil there isn't any!!!

    The same applies to 2-stoke Chinese bicycle engines - if it's not leaking oil there isn't any!!!
  10. nctrooper1072

    nctrooper1072 New Member

    Been thru 4 engines..( 80cc china ) Has always been a cracked piston ring.. Need to run 16:1 ratio.. Spray bugs.. It'll last longer .. Also the exaust gasket may be blown a lil...
  11. Purple Haze

    Purple Haze Active Member

    There's a lot of good advice here, but y'all missed one. Most sparkplugs have a sealing ring on them that is a type of crush sleeve. If you loosen the plug more than a couple of times, it will not seal properly and you will have an oiley mess on top of the head. Once you do your plug chops and get the mixture right, put a new plug in.