STILL no spark

[DavidRysewyk]

HELP!! I am trying to get a 48cc quad running for my grand children. It had a lot of extra wires on it(someone had torn out the remote system). I removed all the extra wiring and switches, replaced every electrical component except the solenoid, and rewired it back to the very basic design needed to run. Problem is, I can't, for the life of me, get ANY spark out of it. Didn't replace the solenoid because it turns over fine, and solenoid doesn't affect the spark. Am I missing something really simple?? I've checked out every diagram I can find, I am at my wits end. This was supposed to be ready for Christmas, and I have spent days trying to get spark. I visually matched up every part I bought. Anything you could suggest would be greatly appreciated. Thanks in advance, David

[Landsvw]

Hi,
I’d start off with a google search for

Basic wiring diagram chinese

This will give you some indication of how the system works. Gotta have a good pickup coil, which is probably under the flywheel (sometimes not tho), a good ignition coil and a good CDI box, and the wiring then has to be correct. A OHM/Volt meter is a good thing to have to Verify kill switches, key switches, and whether voltage is getting to where it’s supposed to be. Also a brand new spark plug, and, also, make sure the spark plug boot assembly is good and screwed on the wire correctly.

[GrandKidsMX]

Often it's the stator. If the coil & CDI have been replaced or checked, it's likely the source coil on the stator.

Go to TBolt USA and contact them about a unit that will fit your machine.

[Bruces]

2 or 4stroke ?

[DavidRysewyk]

Originally Posted by Landsvw

Hi,
I’d start off with a google search for

Basic wiring diagram chinese

This will give you some indication of how the system works. Gotta have a good pickup coil, which is probably under the flywheel (sometimes not tho), a good ignition coil and a good CDI box, and the wiring then has to be correct. A OHM/Volt meter is a good thing to have to Verify kill switches, key switches, and whether voltage is getting to where it’s supposed to be. Also a brand new spark plug, and, also, make sure the spark plug boot assembly is good and screwed on the wire correctly.

Thanks for the reply. As I stated, I've replaced everything but the solenoid. I've got about 7 different wiring diagrams, all of which are basically the same. I've got a good multi meter, but without knowing the corresponding values, it's next to useless, and I cant find them anywhere.

[DavidRysewyk]

Originally Posted by GrandKidsMX

Often it's the stator. If the coil & CDI have been replaced or checked, it's likely the source coil on the stator.

Go to TBolt USA and contact them about a unit that will fit your machine.

Thanks, but I put in a new coil, stator with pick up coil, CDI, voltage regulator, and bypassed all the unnecessary switches. The only thin left, I think, is that one of the new parts is faulty. I need to test them, but don't know what numbers to look for.

[DavidRysewyk]

Originally Posted by Bruces

2 or 4stroke ?

4 stroke.

[Landsvw]

Well, let’s see.. start with the pickup coil, under the rotor or wherever it is (for example on my old XR600 it was on the other side of the engine all by itself). I think when the engine is spinning over, some kind of voltage should be being produced, in spikes, every time the magnet crosses the pickup. Probably AC current. Validate this and don’t really worry about the actual Voltage (don’t accidentally check the lighting coils). Then, verify this signal is getting to the cdi. On the other side of the cdi, at the coil, there should be a voltage, but again, not too worried WHAT it is but again, it should be (I think) a fluctuating voltage and probably AC. Although there are DC CDI’s too... I’ve seen them and when buying them you have to pay attention to the difference. At that point, if there is voltage all the way to the coil and it seems to be reasonable (by the way, search for how to test more common bikes like Suzuki or Yamaha to get a close test voltage maybe since the Chinese ones are missing or vague), then test the coil. Coils usually have a standard type of test so again, use a Japanese bike testing voltage and/or closed/open between the 2 or 3 wires (varies from different bikes). That’s about it! Other than switches, and bad wires, a pickup coil, a CDI doing the right thing and then a good coil, good output lead, good cap and a good spark plug should give you spark.

Also, bad grounds, and also, kill switches usually ground out the CDI so check to make sure those aren’t grounding out things when they are not supposed to.

[Bruces]

I suggest looking at a Honda crf 50 manual ,your bikes electrical is based off of the crf ,but you have lights and crap that the crf doesn’t use .

[Landsvw]

Here’s a very basic picture of the wiring I just found on here...

https://www.bing.com/images/search?v...x=63&mkt=zh-CN

[Landsvw]

So, make sure the smaller plug, with black and red: black not grounded. Red, has 12 volts.
Then, make sure there is a pulse from the pickup coil. Then, make sure that there seems to be 8-12 volts Pulse at the coil? I think maybe it’s 8 but can’t remember... I think there are ways to trick the coil into sparking. I think it’s by using 8 volts directly to the coil input wire and quickly brushing it with the voltage. This should create a spark at the plug, but I could be wrong on that... also, a magnet run over the pickup coil should creat a spark too, at the spark plug, if all the other things are hooked up right.

[DavidRysewyk]

Originally Posted by Landsvw

So, make sure the smaller plug, with black and red: black not grounded. Red, has 12 volts.
Then, make sure there is a pulse from the pickup coil. Then, make sure that there seems to be 8-12 volts Pulse at the coil? I think maybe it’s 8 but can’t remember... I think there are ways to trick the coil into sparking. I think it’s by using 8 volts directly to the coil input wire and quickly brushing it with the voltage. This should create a spark at the plug, but I could be wrong on that... also, a magnet run over the pickup coil should creat a spark too, at the spark plug, if all the other things are hooked up right.

I have the 5 point cdi, but I believe the only difference is the extra ground. More importantly, your link also had a pic of the values to look for with a multi meter, which has been very hard to locate. I'm going to jump back on this little SOB first thing in the morning. Thanks again.

[Landsvw]

Welcome! I just stumbled on that link reading someone else’s electrical issues last night. I had to fix my Roketa (former bike) and it was the CDI box. After all the old motorcycles I’ve had I’m getting fairly good at electrical troubleshooting... keep us posted as to results!

L