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Post by markek on Nov 8, 2010 11:39:34 GMT -5
I have a 49cc 2 stroke engine with electric start, lights, etc. I'm not getting spark to the plug.
My ignition coil has 2 wires, 1 goes to ground and the other I'm pretty sure goes to the key switch. Can anyone tell me if when I turn the key if that is supposed to provide 12v to the coil? I currently have the one wire that comes from the coil wired to a black/white at the key switch which I'm assuming would be the kill switch.
I think I have the other wires wired correctly from the keyswitch (engine cranks with electric start switch, blinkers work, horn works, looks like gauges work).
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msb09
Junior Dawg
Posts: 7
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Post by msb09 on Nov 8, 2010 19:48:20 GMT -5
I can't say if the wire should come directly from your switch, however, 12v should go to one coil terminal, while the other coil terminal is then connected to ground via your points (either mechanical or electronic). There are many wiring variants, depending on the vintage of the machine.
But basically, here's how a coil works .... 12v is fed thru the coil's outer windings to ground via the mechanical or electronic points. This current causes the coil's outer windings to build up a magnetic charge. This charge in turn causes the coil's inner windings (which are connected to the spark plug wire) to develop a reverse magnetic charge.
When the mechanical or electronic points open and thus break the 12v circuit's path to ground, the outer coil's magnetic charge is lost. Because of this, the charge of the coil's inner windings is released to the spark plug which - BAM - ingites the fuel/air mix.
The coil can be bad if A) either of the 2 windings get a break B) the 2 windings come in contact with each other due to failed insulation or C) the outer winding becomes in contact with the coil's case - and therefore the scooter's ground (frame) due to failed insulation.
Hope this helps.
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Post by trailheadmike on Nov 8, 2010 19:54:47 GMT -5
FWIW, I recently lost spark, and after checking and checking, I pushed the spark plug wire lead firmly into the coil and I've been sparking ever since.
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Post by tvnacman on Nov 8, 2010 20:10:28 GMT -5
Mark no 12v to coil on a scooter (it is different than an old car with points ) tell me more about your scooter ? what year , do you know if you have a cdi
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Post by markek on Nov 8, 2010 22:14:43 GMT -5
msbo9m,
I'm thinking the coil is bad, just not sure. When I put 12v from one of the key switch wires to the wire that goes to the coil I keeping blowing a fuse. I guess if I could determine in fact that when I turn the key that the wire should provide 12v directly to coil then I know the coil is bad.
Do you know how the kill switch is wired to the key switch?
Thanks,
Mark
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Post by markek on Nov 8, 2010 22:19:08 GMT -5
tvnacman,
It's a 49cc mini chopper. Just can't find any information or responses from other forums. This forum has already provided more info in a couple days than others have in weeks.
Trying to learn as much as possible about the engine and wiring and the scooters seem to be pretty similiar.
Mark
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msb09
Junior Dawg
Posts: 7
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Post by msb09 on Nov 9, 2010 21:58:46 GMT -5
Sounds like you have a more modern machine, like tvnacman says it's not as straightforward as an older points setup. The kill switch can be wired many ways to either ground or open the circuit.
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Post by markek on Nov 10, 2010 20:43:11 GMT -5
It's a chinese mini chopper. Not sure how modern it is. I'm just trying to figure out if either the coil is bad or if maybe the kill switch is preventing it from sparking.
I'd hate to spend the money on a coil and find out that wasn't even the problem.
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Post by tvnacman on Nov 10, 2010 22:22:59 GMT -5
Mark If you help me and answer my questions " I WILL HELP YOU GET IT RUNNING "
how old is the bike about ? does it have points ? how many wires are on the ignition switch ? Take wide pics of electrical parts. STOP JUMPING THE COIL ! take a deep breath be my eyes and hands
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Post by markek on Nov 11, 2010 17:06:15 GMT -5
Here's what I know, which isn't much. The bike is an HL2000 Super Chopper. I have no clue how old it is. The engine is a 49cc 2 stroke. At least I'm pretty sure it's 49cc. I don't think it has points. Where would I look? It does not have a CDI that seems a lot of other bikes have. There are 2 prongs to ignition coil. One goes to the other ground wires and the other i think to key switch I will take some pics and probably have posted tomorrow.
Thanks in advance,
Mark
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Post by tvnacman on Nov 11, 2010 17:32:11 GMT -5
mark are you with me and do you have time now
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Post by markek on Nov 11, 2010 17:42:17 GMT -5
tvnacman,
Unfortunately I can't tonight (friend passed away and the showing is tonight).
Mark
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Post by tvnacman on Nov 11, 2010 18:18:25 GMT -5
sorry for your loss
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Post by markek on Nov 13, 2010 14:32:42 GMT -5
tvnacman - Thanks.
Can someone tell me how to post photos.
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Post by tvnacman on Nov 13, 2010 16:08:26 GMT -5
Mark when you figure it out please teach me
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Post by lshigham on Nov 13, 2010 17:01:55 GMT -5
tvnacman - Thanks. Can someone tell me how to post photos. Simple, click post reply down the bottom and then add attachment. Post as usual.
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Post by D-cat on Nov 13, 2010 19:04:51 GMT -5
If making multiple images per post, host your images on another site (like photbucket, suggest using 800x600 resolution or less), then use the "IMG" BBCode tags. [ IMG] host.site/direct/link/to.jpg[ /IMG]
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Post by markek on Nov 13, 2010 22:06:35 GMT -5
Here are some pictures. Attachments:
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Post by markek on Nov 13, 2010 22:07:53 GMT -5
Another pic. Attachments:
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Post by markek on Nov 13, 2010 22:08:39 GMT -5
Last pic. Attachments:
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Post by D-cat on Nov 14, 2010 23:57:52 GMT -5
Looks like from chopper3.jpg that you have a good old fashioned magneto ignition. If so, it will not have a +12v input; the coil will be charged by a magnet on the flywheel. Does this thing have a points and condenser system hiding somewhere? Condensers burn out fairly regularly, coils less so, but you still want to make sure there's no premature grounding of the spark wire.
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Post by markek on Nov 15, 2010 15:15:12 GMT -5
D-Cat,
The specs say that it has a CDI ignition. Unfortunately I don't know what that is or if it has points or not. What I do know is your right about the magneto. The coil sits (slight gap) on the flywheel and appears to be magnetized.
The one wire from the coil goes directly to keyswitch. Are you saying that when I turn the key that the wire shouldn't provide 12v directly to the coil? I have tried to give the coil 12v and it always blows the fuse.
I think that the coil wire should go to the black/white from the keyswitch which I think is the kill wire. There is no voltage to the black/white wire when I turn the key. Wiring this way does not blow a fuse, but then again I do not get spark.
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Post by markek on Nov 16, 2010 17:18:11 GMT -5
D-Cat,
Would a bad magneto stop the spark to the plug??
Where is the magneto? Is there a way to check it?
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Post by markek on Nov 16, 2010 19:03:47 GMT -5
After a little research I think I found that the magneto is really what I call my ignition coil (i think). Attachments:
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Post by D-cat on Nov 16, 2010 23:33:23 GMT -5
It may use electronic ignition timing instead of points, but I don't see how it would be CDI. Do you have a 4 wire ignition switch? I would think that any wire headed to the switch would be a kill wire, grounded when you want to shut the engine off. The other wire has to go to whatever is the timing control. Sorry I'm being kind of vague here, I don't exactly have a manual on this and judging from the photos, I'm not sure it would do much good anyway. The way I understood it, the magneto was the assembly of the bar and coil. I could be wrong, but it was one of those things to me that was inconsequential. To answer your question, yes, if it is bad, it will not spark. Another thing to check for is rust on the magnet. If it is rusty, it should be sanded down and cleaned off, then the magneto gap should be reset to about .010". The magnetic pull is strong, so you want to use a disposable spacer that isn't of a magnetic material; I have always just used matchbook cover.
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Post by markek on Nov 17, 2010 17:01:01 GMT -5
Specs say it has a CDI Ignition. 2 wires from ignition coil - one to ground other to keyswitch.
I'm guessing the wire from the coil goes to the kill switch wire (black/white) on the keyswitch.
What I'm trying to figure out is when I turn the keyswitch the black/white does not have voltage. Is there supposed to be a different wire from the keyswitch to the coil so that when I turn key it gives coil 12v??
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Post by D-cat on Nov 17, 2010 17:50:39 GMT -5
No.
The kill wire grounds out the coil when the ignition is off. This eliminates the spark and forces the engine to turn off. The coil gets its power from the magnet on the flywheel, nowhere else. This kind of setup is similar to a lawn mower engine, there doesn't even need to be a battery for it to run, as long as you can get the motor turning.
Typically with a magneto setup, there will be a set of points and a condenser hiding under the flywheel or or somewhere else that is actuated by the drive shaft. Technically speaking, the condenser is a capacitor which is discharged at point rejoining causing the coil to fire a spark, so that might be what this is referring to as CDI (pretty lame if it is, IMO). You can get electronic units to replace the condenser too, but I'm getting ahead of myself here. We haven't even verified how this motor does its timing, or even if it does (it is a 2-stroke, maybe it's meant to fire at the magnet's pass with no timing adjustment?). If there is no timing adjustment device, no points, no condenser or any other ignition control, then we need to figure out why the coil isn't firing on what should be a dead simple setup.
Did you install this coil or did it come wired as it is? Did it ever run in your possession? Under what circumstances did the motor cease to start?
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Post by markek on Nov 17, 2010 19:01:06 GMT -5
The engine has never run while it has been in my possesion. I've mainly been trying to get the wiring straight. The 5 wire 3 position keyswitch was missing so I think I have connected the wires to a new one correctly (lights, gauges, blinkers, electric start, etc. all work).
I think you are correct when you say the coil fires at each magnets pass because I don't think there are points or condenser. If this is the case then does turning the key give the coil 12v?
If not, then the wire coming from coil goes to kill switch. But how does this work. When I turn the key it doesnt prove voltage to the coil, so when I turn the key off how would this kill the coil?
When the engine starts maybe this gives the wire to the kill switch voltage and when you turn key off it kills the voltage??
Thanks for you interest and help by the way!!!
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Post by D-cat on Nov 18, 2010 10:11:04 GMT -5
How the kill works is when the switch is in the OFF position, it closes the kill circuit to ground so the coil can't build a charge. No charge, no spark. The kill wire should remain open (disconnected from anything) while the ignition is on. Again, there is no +12v connection to the coil, this I am certain. It's possible there should be one to our absent CDI box (not usually), but definitely not to the coil. This engine is designed to run even if you had no electrical components at all (save the ignition itself); think "scaled up chain saw" engine. I'm still disturbed by the lack of a points system or physical electronic ignition box (e.g. CDI). I'm thinking it's missing an important component to flooding the coil with enough voltage to spark. You have 2 wires on one connector off that coil, I think they are supposed to go to the capacitive discharge unit. Looks like something like this could just plug right in: tewarehouse.com/7-01749
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Post by markek on Nov 18, 2010 13:22:24 GMT -5
So there's no voltage to coil from this kill switch wire. I'm still a little confused with this kill switch. When the engine is running does it provide voltage to kill switch and then when you turn key to off it kills (or grounds) the wire so that engine stops??
Not positive if it has points but I do know it doesn't have a cdi box that other scooters or mini bikes have. On those it seems that the kill switch among other things go right to cdi box.
I guess the next step would be to replace the coil, problem is I'd like to be more positive if thats the real problem. Maybe the kill switch is somehow stopping it from getting spark?? Not sure exactly how I would bypass the kill switch because i don't even know if I have it connected correctly.
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