Happy Times "no start" - "hard start" possible fix

Discussion in '2-Stroke Engines' started by arceeguy, Sep 22, 2008.

  1. arceeguy

    arceeguy Active Member

    Hey guys,

    Just finishing my 4th build with a "Happy Times" bicycle engine and experienced my first "no start" condition from a brand new engine.

    I was getting a "no spark" condition and swapped out a new CDI, which didn't do any good. The magneto coil measured continuity from ground to the white wire, and blue wire. It would light up a night light bulb (dim, but lit) connected to the blue and black wires, so there was output.

    Turns out the problem was the air gap between the rotor magnet and the magneto frame. It was too wide, and the magneto output wasn't high enough to trigger the CDI. I used a business card and a large pair of vice grips to close the gap on the magneto coil.

    Now, the engine starts with just a momentary "popping" of the clutch lever at slow speeds. I made the adjustment to my other bike, and it starts a lot easier. I would have to pedal to a pretty high speed and pp the clutch before it would start, and now I can just pedal at a slow pace and pop the clutch to get it started with little effort. The same night light now glows a bit brighter when connected to the magneto, so the output went up a lot by closing the air gap.

    Hope this helps others!


  2. bluegoatwoods

    bluegoatwoods Well-Known Member

    Well, how about that? Something new.

    That coil "frame" looks fairly beefy. You can close that gap with vice grips? Or did I miss something?
  3. arceeguy

    arceeguy Active Member

    Yup - I used a pair of vise grips clamps. The coil frame isn't hard to deflect the 10-15 thousands of an inch that was required to get it running. The new owner picked it up a couple of hours ago and it started up in an instant.

    No more Moon Doggies at Walmart, either online or in stores. Woof........
  4. ibdennyak

    ibdennyak Guest

    hmmm, wonder if that was my problem.....seemed to replace them every time it rained. :???:
  5. Moon Doggy problems?
  6. arceeguy

    arceeguy Active Member

    They are sold out of the puppies.
    I have a brand new Huffy Cranbrook that will be my next build. Single speed with coaster brake - should be interesting.

    ibdennyak - I have no idea why a coil would fail if it got wet. The copper wire is enameled, and it looks like they dip the whole assembly in some sort of varnish.
  7. ibdennyak

    ibdennyak Guest

    That was my thought too, espexially after all the wsterproofing measures I took. Of course, the climate here is kind of extreme......I've seen rain 24/7 for 61 days already. Put it this way...couple years ago, I saw something on the chrome bumper of my truck. There was a mushroom growing on it. :shock: Never saw that before. Thought maybe the constant moisture causes a partial short somewhere. Oh well.
  8. arceeguy

    arceeguy Active Member

    I guess cars up there don't last too long either.

    Maybe try giving the magneto and magnet a shot of Mercury Marine "Corrosion Guard" spray, or Boeshield T9. Might not be a bad idea to spray the CDI where the high voltage wire screws in. People coat their entire outboard engines with this stuff to keep the electronics from failing.
  9. bluegoatwoods

    bluegoatwoods Well-Known Member

    You know, turning to marine products is a good idea. They must have to deal with water issues (of course) but it wouldn't occur to us land-lubbers.

  10. arceeguy

    arceeguy Active Member

    Every year, I wash the underside of my cars and give them a coat of Boeshield T9 on every visible square inch. I also clean the engine compartment and do the same. Makes it a lot easier to work on an old car where the fasteners aren't all corroded and frozen. Stuff is great weather you live by the ocean or in the "rust belt".
  11. impression

    impression Member

    wow, i took the cover off my magneto and it's quite close already, but it's a '*****' to start my bike :(
  12. Skyliner70cc

    Skyliner70cc Active Member

    Impression, spark is just one part of the equation. Fuel and air are the other 2 key components needed to make it all work well.
  13. billpb1222

    billpb1222 New Member

    i thought the coil was in a sealed housing. isn't that where the spark plug wire is attached? i attached mine to vertical frame with cable ties and electrical tape. i can't achieve my first start either. i am pedalling hard then popping clutch. chain jams or no sound of firing. please help.

  14. arceeguy

    arceeguy Active Member

    The stator coil (magneto) is on the engine opposite side of the clutch under a cover.
  15. AussieSteve

    AussieSteve Active Member

    Well done arceeguy. This is a very sensible mod for these engines, as long as the core is bent carefully to avoid creating gaps between the laminations and especially for those running lights from the white wire, (although that's not the best idea since it robs engine power).
    I haven't done it yet, but I will tomorrow. My engine takes a little longer to start than it should and the spark is a little weak, so this might help. It makes good sense and will definitely increase the magneto's power output.
    I'll report back in a day or so regarding results.
    ... Steve
  16. billpb1222

    billpb1222 New Member

    could someone show me in the way pics or instructions how to increase the magneto power output. should i disconnect the white wire from headlight?

  17. bluegoatwoods

    bluegoatwoods Well-Known Member

    I would disconnect that white wire, tape the end and forget it. I'm not an authority on this but the consensus that these are not very good light power sources and can lead to trouble seems clear enough. Why take a chance when you can get light from other sources?

    As for the magneto, look at the front of the engine where the wiring enters. You'll see that it actually enters near a cover that can be removed. Under that you will find a magnet surrounded by a horseshoe shaped coil. Then follow the OPs directions regarding vice grips and business card "feeler gauges" and you should have it. I might give it a try myself. Good luck.
  18. AussieSteve

    AussieSteve Active Member

    Well, I bent my coil core in to a business-card gap and it definitely improved starting. It usually takes about 20 feet to start mine and now it does it in half that.
    For anyone with a weak spark, this is worth a go.
    ... Steve