See full version: How do I know when my CDI is bad
These mentioned symptoms can be confusing and one has to be careful before concluding that the problem is with the CDI. When the fuel pump has a problem, spark plugs or coil packs are faulty, you would observe similar symptoms. Therefore, the only way you can tell whether your CDI has a problem is by confirming that everything else is in the right condition. The reason is that there is no particular way of testing the condition of the CDI. here
The CDI in your scooter is linked to the ignition. Therefore, if it is in good condition then you will have fewer or no issues with your ignition. It plays the role of storing electrical charge and increasing the spark power on the spark plug.
Whenever you overwork it, it will not serve you for long. One advantages of the CDI is that they are not sensitive to shunt resistance. The CDI box, however, does not give enough ignition efficiency because its spark duration is short. [links]
The CDI is not easy to diagnose because the observable symptoms of a faulty CDI box can lead to different directions. Sometimes, a bad CDI does not cause sparks at all. Again, when a CDI box is about to go bad, it can lead to misfires, issues with starting, rough running or even stall the motor. more
How is my CDI?
If these tests do not check out, you will need a new regulator/rectifier. [links]
Faulty wire grounds are a very common problem, but can sometimes be difficult to track down. Symptoms of a bad ground can range from a completely dead bike to electrical components working intermittently. Checking all of the grounds on your motorcycle can be done quickly if you know where they all are. If you don't, your service manual should have all of the locations noted. more
To begin, you should first check for continuity from the terminal tabs of the connector and then see if anything goes to the ground. Set your multimeter to Ohms to check this. First, use the multimeter leads to check the resistance of the tabs by checking A to B, B to C and then A to C. The multimeter should read under 1 Ohm for all three (make sure to take into account the resistance between the leads). Readings over 1.5 Ohms are an indication that the stator is faulty. more
There have been entire books written on this subject and this guide is not meant to replace them. It will, however, help riders understand what each electrical component's function is and what problems they can cause if they are malfunctioning. The purpose of this guide is to help riders to begin the process of troubleshooting motorcycle electrical problems.
It's possible for your motorcycle to start and run with a bad battery, but that can create even more problems like causing the bike to run poorly and miss. It's also important to make sure that the battery that you use produces enough amps to properly power all of the electrical components.
Pickup coils rarely go bad, but at times they do. Fortunately, they are not that difficult to test. To begin, you will need to unplug the connector. Connect your multimeter leads to the connector and check for resistance by setting your meter to Ohms. Compare your readings with your shop manual's specifications to see if they are within range. You can also check the gap between the coil and the magnet. Make sure that it is gapped to the manual's specs.
Although, if none of the symptoms relate to your bike, there’s a good chance it won’t need a rebuild yet…
However, before tearing your engine apart, there’s several signs that can tell you it has a worn top-end. If you have most or all of the symptoms listed below, you can more than likely count on replacing at least the piston and ring, and possibly a cylinder and head if there is excessive wear. more
To test your engine, you can get a you can get a compression tester (Amazon) to get an actual PSI number that will tell you what condition your top-end is in. For more info and a tutorial on how to check engine compression click here.
Ok, every new crankshaft should be checked for run out before ever installing them. The after market cranks can be out a lot and I have even seen some oem new units out as well.
A crank this is not running true will allow flywheel to run out of round and may be enough to not allow the trigger coil to do it's job or to allow contact with it. This can short the stator.
Where do u see the sign of a short? more
I see signs of a short on the stator coils.
What else could cause a short? [links]
Have you don a run out test on the crank shaft where the flywheel mounts?
Your crank could be running out of round. I have seen this cause stator issues in the past.
I haven't done a run out but it is a brand new crank and bearings.