My project and my starting issues......

Discussion in '4-Stroke Engines' started by Azzaa, Dec 30, 2012.

  1. Azzaa

    Azzaa New Member

    My project is an off road go kart for my boy when he's old enough to use it. In the mean time it's a project for me to pass the time.

    I've acquired a daelim 125 4 stroke air cooled motorbike. I've not seen or heard the bike running, nor has then previous owner. The previous owner suggested it needed a new carb....

    The bike was in a **** of a state. The previous owner had played with the electrics and taken apart most of the bike from what I can tell. Lots of the wiring loom was missing but the essentials are there. So I cleaned the carb and tried to start the bike.. No joy. After a little playing about I found it wasn't getting a spark, so after a lot of head scratching and trying to make sense of the loom, I gave up and thought I'd start from scratch..

    I've got my self a new welder and some tubing in order to build the buggy frame. So since I'm new to welding I thought why not build an engine stand to make it easy to work on the engine and test my new welding skills. Here's the results:


    I've stripped the bike of all I believe necessary for the engine to run and mounted to the stand:

    Cdi box
    Kill switch

    All of which have been checked for continuity, rewired where needed and connected as needed. The rest of the loom has been discarded.

    I have tried everything to get it going. The carb is clean and getting fuel.

    The spark plug is giving a good spark. Held around 6mm from the block it jumps easily when cranked.

    Compression hasn't been tested, I've not got a tester, but one is on the way. But from what I can tell it seems to be reasonable since it has good resistance when cranking and pressure can be felt from the exhaust while cranking. Also air is being sucked from the air inlet.

    I've tried easy start squirting into the air intake and direct into the spark plug hole. Neither tried to start.

    After putting that all down on paper I'm now thinking compression since I seem to have exhausted all other possibilities. Either that or the ignition timing. But I have no timing light or the know how to change it.

    So any help would be much appreciated!



  2. jaguar

    jaguar Well-Known Member

    Try using starter fluid spray to get it cranking. If no success then it's probably timing. If there is enough compression for it to be hard to turn over manually then there's enough compression to run. If you can rotate the crankshaft by hand then you have a very bad leak.
  3. Azzaa

    Azzaa New Member

    Tried starter fluid already, no joy at all.

    No way it'll turn over by hand.

    Any idea how I go about the timing? I've searched hi and lo for a service manual but these bikes are none to common here.


  4. jaguar

    jaguar Well-Known Member

    mark on some crank part to note when the piston is at top center (which you can know by use of a screwdriver inserted where the spark plug goes). Get an automotive timing light for $20. Connect it to a car battery. Put the detector on the spark plug wire. crank the engine to see if it is sparking before TDC (top dead center). If not then you have serious timing problems.
  5. BigBlue

    BigBlue Active Member


    This is the second post in the last 2 days for someone looking for help on a 125cc motorcycle. I guess this forum is becoming a motorcycle repair forum in addition to motorized bikes.

    You have to make sure the engine is properly grounded and look for any safety neutral switches that might be wired to the CDI that may prevent your engine from starting. I assume that you are using the original CDI. Remove the kill switch from the circuit as it maybe causing the problem. That is one of the first things I recommend in a no start situation.

    I found this manual for a Daelim Daystar in .20 seconds from Google that has a wiring harness that may help:

    Good Luck,

    AKA: BigBlue
  6. Azzaa

    Azzaa New Member

    I signed up for this place after a lot of searching. It seemed really knowlegable and helpful. Truth is at first I didn't realise it was a forum for motorised bikes :dunce: over here we call motorcycles - motorbikes. So you can see my stupidity there lol.

    Back to the engine... I've not managed to find a cheap timing gun as yet, I'll keep looking. Is there another way to roughly time the engine?

    The electrics should be good, like I said I've rewired the whole thing and I'm getting good spark. The kill switch seems to work fine. When activated I get no spark at all.