crankshaft reapair

Discussion in '4-Stroke Engines' started by mckanyx, Feb 13, 2011.

  1. mckanyx

    mckanyx New Member

    I own a 110cc 4-stroke engine which had been removed from a pocket bike.

    this engine has numerous problems.

    some of which have been repaired.

    others have not yet been repaired.

    I would like to remove the crankshaft in order to replace this part but it appears to be pinched into place in relation to what is riding on one end of the shaft.

    the crankshaft requires to remove the magneto before it will become loose of the rest of the engine.

    the bell shaped magnet is not budging.

    there are not any more fasteners left to be removed on this portion of the engine.

    I am unsure of whether to pry with shop tools or if there is an easier way to take the magnet off without destroying anything.

    The piston head also looks like it was meant to be removed. I haven't had to remove this part before and I have not found any related instructions or user advice for this type of engine on the Internet.

    Will this be the type of part that will need to be destroyed in order to have it removed from the engine?

  2. HeadSmess

    HeadSmess Well-Known Member

    get on ebay, look up DHZ or similar, and get the puller.

    about ten bucks :) also supplies the cranks, buuuut...

    i know exactly what engine youre dealing with, and um...

    its sorta cheaper to get a better, slightly bigger engine :(

    (also on ebay!)

    trust me, i have at least 10 of em...

    you can also try heating(with blowtorch or something reaaaaalllly hot) the hub of the magneto, then tapping it may work...may...
  3. mckanyx

    mckanyx New Member

    What should be used to clean the interior of the engine?

    Can an engine handle the solution of a carburetor cleaner or should another recommended product replace a combustible spirits?
  4. Silvaire

    Silvaire Member

    Buy the puller.

    Heating the stator will DEMAGNETIZE the magnet!
  5. mckanyx

    mckanyx New Member

    8" 3-arm puller did the trick.

    :cool2: It might better to install a larger engine.

    There are counter-sunk screws that are fastened into a disc underneath the magnet.

    They both had to be bored and, the bores tapped for replacement parts.

    This 7.5 hp engine had to be stripped part for part in order to extract the crankshaft and piston from the outside.
  6. HeadSmess

    HeadSmess Well-Known Member

    best substance to use for cleaning engine internals?

    are you really ready for this?


    if youre doing a complete dismantle, water and degreaser(detergent, not solvent). for just a quick job, yes, just petrol...

    the trick is to get a stove, and some HUGE saucepans. fillem up. lets the parts boil for a good half hour! poke em! scrub em! agitate them! stir em up!!!an old head with baked in dirt may take hours!!! and then still not be clean!!! :( .

    keep internals seperate from the cases and really filthy bits... saucepanSSSSS

    fish parts out, one by one, while still boiling! tie wire is an idea im yet to try... :rolleyes:

    the water will then evaporate almost instantly. steel parts may tarnish, but they WONT RUST! unless they STAY wet...

    lay the (hot!!!) parts out neatly on a cloth... spray with some WD40, light oil...etc.

    now replace all the water in the pans. repeat process.

    now wash your hands. tools. bench. wash! spotless! this is heart surgery!!!!

    everything is clean, reassemble.

    dab of oil to all moving parts, turn over by hand to check everything works, done :)

    those fingers should still be spotless at this point...
    Last edited: Feb 24, 2011
  7. GearNut

    GearNut Active Member

    The best detergent I have found so far for the boiling technique is original Tide. Not the one with bleach! It has TSP in it which really helps remove the oil and grease out of the pores of the metal.