Oil in Magneto

Discussion in 'Electrical' started by lucas, Aug 26, 2010.

  1. lucas

    lucas Member

    I have a question. I have oil collecting on my magneto housing. Not sure how bad of a problem this is. Bike runs fine haven't noticed any difference. except i have to drain it about every 100 t0 200 miles. oh its a sky-hawk 66cc.

  2. GearNut

    GearNut Active Member

    The crank shaft oil seal behind the magneto rotor has either popped out or has failed.
    I recommend fixing it asap.
    Magnetos do not like to be oily and it is also an air leak into the crank case.
  3. lucas

    lucas Member

    not sure how to go about taking that apart. anything i should keep in mind so i dont screw myself in the long run would help.
  4. GearNut

    GearNut Active Member

    Mark the outer face of the rotor with a sharpie pen, crayon, or scratches.
    It can be installed backwards and doing so will upset the ignition timing.
    Marking it insures that it will be re-installed correctly.

    Remove the stator before messing with the rotor. That way you will not be fighting the magnetic attraction between the two.

    Superglue the woodruff key back into the crank shaft. That will prevent the magnets in the rotor from removing it each time you try to re-install the rotor.

    It is easiest to remove the rotor with an automotive battery terminal puller. They are cheap at auto parts stores, even cheaper at a 99 cent store.http://greatnecksaw.com/product_info.php?pName=battery-terminal-puller
    Last edited: Aug 28, 2010
  5. lucas

    lucas Member

    So as for changing the gasket that went fine. took a look inside my cylinder housing, massive wear going piston toast. ordered 1 of each. just swapped in a new motor on my commuter bike. the one with the probs has around 6,000 miles on it. first problems ive had with this kit since i got it.:veryangry:
  6. GearNut

    GearNut Active Member

    6K miles on a HT? I'd say you are doing pretty good if you are just now having problems with it.
  7. Artspoke

    Artspoke Guest

    Is there a trick to getting the old crank seal out? I can see two small sections of mine missing - they were actually hanging out in the oil sludge in the bottom of the magnet cover! I've just ordered a new seal, but I can't seem to get the old seal out. It looks like there's a metal spring inside the black rubber. ! ??

  8. Artspoke

    Artspoke Guest

    here's a picture

    I took a closeup of the seal I just reordered - it's really stuck in there! I saw some posts about hammering the new one in . . . but first I gotta get this one out

    Attached Files:

  9. HeadSmess

    HeadSmess Well-Known Member

    what you need is a hook.

    you need to get some piano/spring/music wire. 1-2mm. preferably straight. sharpen one end, curl it into an 8mm hook...slip it in between crank n seal, pull it out :)

    there is a fancy 89 dollar tool you could buy from somewhere but i live in da bush :)
  10. GearNut

    GearNut Active Member

    I drill a teeny hole through the face if it. Be very, very careful that you do not scratch the shaft or hole with the drill bit. I also use a piece of tube to act like a drill stop so I don't go in too far and hit the bearing behind it. You only need to go in about 1/16 of an inch.
    Now use a skinny sheet metal screw and carefully screw it into the hole. Once again, do not go in too far. You only need the first 2 or 3 threads to grip the seal. Now grab the screw with pliers and pull out the seal.
  11. aaronwilde

    aaronwilde Member

    So my magneto case seal has been leaking a little bit for a while now, i just upgraded my spark plug to a ngk from a chinese plug, and added an expansion chamber. The bike is much faster accelration now, better hill climbing, and 10kmph more top speed. (would have got a magneto seal for 2 bucks but they were all out at the time and i figured a tiny leak wouldnt hurt)

    I was riding though and ntoiced when I hit around 40-45kmph speed the engine really starts to open up and it starts going to about 50 maybe even 55 kmph.. then with WOT it just slows down on its own to about 40 ish. After a few seconds it starts going faster again speeding up to 50.. It will repeat this.

    During my ride all of a sudden I am hearing a weird sound and the bike is not running right, only about 60% as fast as before. It bogs tremendously and won't go high RPM with or without the clutch engaged. I got home and checked my crank clutch side case - It is fine. I check my magneto case - 2 big spoon fulls of oil, at the least. All over the place. Has my magneto seal finaly blew a nice hole? Would that magneto side crank case leak be whats making the bike run crappy all of a sudden?

    I was a bit worried that something inside the cylinder of the engine went ( bearing or something ) but would the bike even run at half if something in the engine itself went? Does this make sense?

    -UPDATE- Okay so I did some more searching and It isnt the easiest to start either - I live on a hill so I just go down the ally way but it doesnt get/stay started for about 30 seconds. And i read that this case seal leak is as bad as an intake leak. So that means it would run poorly. Bingo?
    Last edited: Oct 21, 2011
  12. FelipeCobu

    FelipeCobu Member

    Yes bingo!

    With the seal leaking this hard, there isn't pressure to transfer the air to the combustion chamber.

    Felipe Cobu
  13. bidardian

    bidardian New Member

    I got the same problem now,but it's a really tiny leak at the magneto housing
  14. crassius

    crassius Well-Known Member

    you may just need a new seal. but be sure to pry up on the end of the crank there and see if the main bearing has gotten loose (crank should not move at all up/down)