NEW INSTALL, HARD TURN NO SPARK

[aggie]

So I just purchased a china girl on amazon, got it for a deal. Looking for transport while I am in college, and also looking to learn from.

I have had the most difficult time trying to get the engine to turn over. I had followed the s**t instructions to install the engine, but initially I had an issue with the back tire locking up. So my first instinct was to think that the piston was stuck, so I decided to put some motorcycle oil directly though the spark plug hole. I also considered that there was some tension between the clutch and the chain that created some sort of bind.

Tonight I decided to break the drivetrain down, removed the sprocket at the engine. Using a power drill (with the cylinder filled with approximately 1/3 oz of motorcycle engine oil, I turned the piston until it was freely moving.

Initially , the wiring diagram had blue and black from the engine block and red and black from the CDI, in addition to the kill switch wiring. After setting the system up, I decided to install a toggle on/off switch to be a more reliable engine cut-off. The initial wiring diagram is as follows:

kill switch +
|
red CDI wire--(splice)--blue wire
/ \
CDI magneto housing (no white)
\ /
black CDI wire --(splice)----black wire
|
kill switch (gnd)

 

[aggie]

since it concatenated my post, I will post the rest:


Which the kill switch essentially grounds out the spark

I decided to remove the button switch and add an on/off toggle switch, so I decided to follow forum instructions which led me to the wiring diagram:


red CDI wire--(splice)--blue wire
/ \
spark < CDI magneto housing (no white)
\ /
black CDI wire --toggle switch--black wire

Now I am not certain this was the correct method, but from what I have read (probably heresy), using the toggle in the black (ground) wire is best to break the circuit without receiving a self inflicted shock toggling it.

I'd like to note that all connections have been retrofitted with a lineman's splice.

Currently, I have no spark. I am able find continuity all the way up to the red/blue splice before the magneto, but nothing from the R/B splice to the spark plug, although that may very much be the nature of the CDI, I am unsure.

I will say, that everything it's taken me to set up this engine has been nothing short of a disaster.

Wouldn't turn
No spark
No continuity from before CDI to spark plug
Hard pedaling
Poor/No clutch engagement
No engine firing
Engine has never being started

If anyone can offer some advice, I wold greatly appreciate it. How should the black wire be routed? Should I just ground it to the bike frame and use the toggle switch on the red/blue wires? I am almost at the point to which I am going to get readings from every lead point through the system, something is telling me that there is an issue with the CDI wiring.

 

[FurryOnTheInside]

I have no spark either.
I am relying on the tachometer to tell me so.
I didn't bother with any kill switch. I'll use the choke and stall it so it gets a bit of extra lube as it chokes out.
I replaced the plug, plug wire and boot with better quality.
I checked that there's good metal to metal contact between the mag, it's four bolts, and engine.
I connected the mag black to CDI black, and the mag blue to CDI blue (or whatever you have).
I didn't get spark so I replaced the mag with my spare. I still didn't get spark so I'll replace the CDI today with my spare (fingers crossed).
Best to have spares of everything on hand anyway in case anything fails.

 

[crassius]

well, sounds like you got way ahead of yourself with mods before you came here to get it running, then start moding

I have no idea what state it is in now, but you don't need any kill switch stuff just to start it (throwing choke on will stop it)

unhook all wires, then hook black to black & blue to blue between mag & CDI to see if it sparks

 

[aggie]

I have no spark either.
I am relying on the tachometer to tell me so.
I didn't bother with any kill switch. I'll use the choke and stall it so it gets a bit of extra lube as it chokes out.
I replaced the plug, plug wire and boot with better quality.
I checked that there's good metal to metal contact between the mag, it's four bolts, and engine.
I connected the mag black to CDI black, and the mag blue to CDI blue (or whatever you have).
I didn't get spark so I replaced the mag with my spare. I still didn't get spark so I'll replace the CDI today with my spare (fingers crossed).
Best to have spares of everything on hand anyway in case anything fails.

Thank you for your response, I fear that I also have a bad CDI myself. I am going to run some test measurements with a multimeter later this afternoon and see if it is in spec.

well, sounds like you got way ahead of yourself with mods before you came here to get it running, then start moding

I have no idea what state it is in now, but you don't need any kill switch stuff just to start it (throwing choke on will stop it)

unhook all wires, then hook black to black & blue to blue between mag & CDI to see if it sparks

I'd hardly call a safety measure a "mod" when it's done in a manner to rectify a potentially dangerous and poorly designed system in place... but I'll give you that, sure.

So I have a toggle between the black wires, and if you read correctly, I have a red from the CDI and a blue wire from the magneto.

black magneto wire <-> toggle switch <-> black cdi wire
blue magneto wire <-> red cdi wire

If I was getting continuity at the red and blue splice, shouldn't I have a complete circuit? I should not be able to check for continuity past the CDI right?

 

[Frankenstein]

Thank you for your response, I fear that I also have a bad CDI myself. I am going to run some test measurements with a multimeter later this afternoon and see if it is in spec.




I'd hardly call a safety measure a "mod" when it's done in a manner to rectify a potentially dangerous and poorly designed system in place... but I'll give you that, sure.

So I have a toggle between the black wires, and if you read correctly, I have a red from the CDI and a blue wire from the magneto.

black magneto wire <-> toggle switch <-> black cdi wire
blue magneto wire <-> red cdi wire

If I was getting continuity at the red and blue splice, shouldn't I have a complete circuit? I should not be able to check for continuity past the CDI right?

Sorry I looked at this page several times and looking at your circuit converted to text is just not clicking.

Take the kill out, hook up the CDI correctly with the magneto, please also give us a freakin idea what cdi you are using. Check for continuity from the mounted magneto armature to the spark plug hole threads, should be near 0 ohms, ditch any paint in the mag housing that would stop it from grounding to the engine.

Your kill switch should be laid in parallel to the CDI, I can't tell but it sounds like you are putting it in series and using it to disconnect the power to the CDI, I don't recommend that if you are doing it like that.

 

[crassius]

except for the old super rat motors, I've not seen a CDI with a red wire - also, CDI units can't be reliably tested with multimeter - if a toggle is used, it should short blue to black on mag

pics will be required

 

[aggie]

That's right, it was originally in parallel, and then I put it in series. The CDI model is General Cheap China Crap.

I can put it back in parallel, but I think it's odd that I was still not able to get a spark with it in either configuration. I am going to test the resistance on the ignition wire and probably break down the magneto tonight and look and see if there is anything that would increase the reactance of the circuit.

Side note: I think the reason I am confusing the red and blue wiring is because I used a stranded copper red/black power wire as an extension to run the wiring through a path along with the other cabling and whatnot. I might see if I have some solid copper wiring to use instead of the stranded to reduce resistance if there is any appreciable amount.

If either of you have any good suggestions for wiring up the toggle switch and/or the ignition, I have pretty much any available wiring methods and hardware at my disposal.

 

[Frankenstein]

Solid won't make much of a difference, we aren't talking about enough current to worry about these things, faulty connections may be an issue.

You'll need to provide more information if you want more help, I would start with checking values of the components, it could even be the plug boot needs the nut on the plug and the plug doesn't have one, can even be a break in one of your wires, I've had some s**tty wire come my way and just the tug from stripping the ends was enough to snap the cheap thin wires inside of it causing open circuits or high resistance. Also had some connectors that would be crimped on simply act as a cutter and litteraly cut the wire off inside the crimp leading to an open line..

 

[FurryOnTheInside]

Solid won't make much of a difference, we aren't talking about enough current to worry about these things, faulty connections may be an issue.

You'll need to provide more information if you want more help, I would start with checking values of the components, it could even be the plug boot needs the nut on the plug and the plug doesn't have one, can even be a break in one of your wires, I've had some s**tty wire come my way and just the tug from stripping the ends was enough to snap the cheap thin wires inside of it causing open circuits or high resistance.

Broken wire is exactly what I found today when I was replacing the CDI. Unfortunately the break is so close to the CDI that I don't think it's worth trying to get it reconnected.
I am sure it was my fault, I was just inexperienced and inept.. I put what I thought was good amount of "waterproofing" around the wires as they enter the sheath that sticks up from the CDI, and then I tried to bend them out of the way of my exhaust, so that pulled the thin crappy wire and it broke.

The CDI wires are very thin.
Odd that they are thinner than the wires on the magneto. The plug wire and boot from the kit are absolute bollox though. The NGK boot and a decent wire are very inexpensive so it isn't worth not replacing them.