Home / GY6 Electricals / GY6 150cc Ignition Troubleshooting Guide: No Spark? This guide covers almost any of the 150cc buggies, scooters, or ATV’s with the standard “AC” CDI setup.  The first version was downloaded over and we’re happy that this information continues to help so many people! Don’t want to hassle with the electrical system? Due to frequent requests from readers of this guide wanting to avoid hacking into their electricals to find the problem, we’ve put together a kit with all of the electrical parts covered here to shotgun the most common “no spark” problems all at once.  Instead of struggling with a multimeter for hours, you can now plug in the parts and be done. Recommended: Ignition Tune Up Kit Reliable vetted parts picked by the writers of this guide. Will fix spark, or your money back. Getting started: How it all works The 150cc GY6 ignition system is fairly easy to troubleshoot in the case of malfunction. There are 4 major components that work together to produce spark, if any of these are defective spark will be lost.

What we will be doing here is troubleshooting these ignition parts starting at the source, and working towards the spark plug. Stator (6th winding and trigger pickup module) To diagnose your ignition system, you will need to do each of the steps in this article, in sequence. Before getting started, take a look at this diagram.  Although there are many differences in wiring between models, most GY6 ignition systems work the same as shown in this illustration.  You’ll want to come back to this for reference throughout the guide. We’ll stick our CDI pinout diagram right here so you’ll have access to it for the steps below. FIRST STEP: BYPASS YOUR SWITCHES A very common cause of no spark is a defective ignition or kill switch. Before beginning to troubleshoot ignition problems, it is best to bypass the switches. How to bypass your switches Create a jumper wire from pin #4 directly to a good grounding spot on the engine. Being very careful not to deform or break the pin, remove the #5 wire from the CDI plug at the harness.

This can be done with a sharp narrow tool like an ice pick or stiff paper clip. Looking from the front of the plug, you will see small metal tabs on each pin which secure them to the plug. Push the tab down and the pin will release. Don’t use force here. Depending on your stator type, you have either 6, 8, or 11 windings. Of these windings, one is dedicated to supplying the CDI with ignition power. air conditioner outdoor unit placementThis winding is usually wrapped in white cloth material and sealed over with clear epoxy.floor model air conditioners canada A simple type of crankshaft position sensor. how much 3 ton ac unitSends a signal to the CDI to let it know when to send fire to the plug. Set your multimeter to read in VOLTS “AC”.

Locate and disconnect the Black/Red and Blue/Yellow wires coming from the stator, where they plug into the main engine harness. (These are both bullet-style connectors) While cranking the engine, use a multimeter to check for voltage coming from the Red/Black (CDI power wire) and the Blue/Yellow (trigger wire) coming from stator. Place the black lead of multimeter on a metal surface of the engine while using the red lead on the tips of the wires. There should be between 20vAC ~ 100vAC coming from the CDI power wire (Black/Red), although much lower voltages will still be able to produce spark. There should be at least 0.05vAC coming from the trigger wire (Blue/Yellow). Write the voltages down and continue to the next step. Stator output: 20vAC minimum Trigger output: 0.01vAC minimum STEP 2: THE CDI UNIT The CDI Unit is powered by the AC current coming from the wrapped stator winding. This current is stored in a capacitor within the CDI unit. When a signal is received by the trigger pickup passing over the flywheel magnet, the CDI will discharge the stored energy into the wires leading to the ignition coil.

Ensure your multimeter is set to read in VOLTS “AC”. Just like before: while cranking the engine, use a multimeter to check for voltage at the two primary wires of the ignition coil. Connect your back multimeter lead to the black ground wire at the coil, and with the red lead to the lighter color wire (usually blue or purple, but it varies). At this step we are checking to see exactly what the CDI is outputting. Write the voltages down and continue to the next step. CDI output: Can be 5% to 30% less than the output from the stator. The minimum we have seen working is around 18vAC. STEP 3: THE IGNITION COIL The function of the ignition coil is to multiply the voltage of the power supplied from the CDI, and to send the multiplied power to the spark plug. Troubleshooting the Ignition Coil: Check for 0.1 ohm ~ 1.0 ohm across the two primary coil terminals. This isn’t exactly definitive, as we have seen working coils with 0.0ohms resistance. The best way to tell if the coil is bad is to perform steps the steps above.

If there is still no spark, the coil is likely bad. STEP 4: SPARK PLUG The plug is very rarely the cause of no spark on the GY6. If the plug is fouled or cracked it may not spark. Ensure that the spark plug is gapped properly.Recommended spark plug gap: 0.6mm ~ 0.7mm (0.23″ ~ 0.27″) Was this guide helpful? Please consider supporting this article and our efforts to provide the best technical support to the GY6 community.  You can purchase our Ignition Tune-Up Kit directly from our online store to ensure that more Tech Center guides like this one continue to be published.  I’ve spent many moons diagnosing nagging air conditioning issues with a 1992 Chevy Silverado K1500 . Research indicates that many other owners have similar issues. In my case, a conversion from R12 had already been performed. Heating worked, control panel worked, but the AC compressor was not engaging. First step: The compressor clutch running? I learned that by bypassing the pressure switch on the AC canister I was able to get the clutch running.

Low pressure and/or a leak seems like a reasonable guess. Trip to mechanic, who performs leak tests and tops off system. He notes that the conversion from R12 has already been performed. AC works for him, he calls it a day. I pickup the truck and notice that the system isnt very cold, and the ‘AC’ light on the control unit is flashing. There are known issues with false readings from the pressure switch. Manufacturer recommends disconnecting the pressure switch from the heater control harness. For the K1500, the wire is green #1 (SEE: LOW CHARGE INDICATOR FLASHES DISCONNECT CHARGE DETECTION # 93-1B-129). BEWARE There are two procedures; one for ‘topkick’ models and one for regular trucks! I perform the procedure and at this point issue seems resolved. I close up the dash and call it quits. Start vehicle the next day, AC is pumping strong, possibly too strong. I smell burning plastic, and the AC control head goes ‘disco lights’ on me. Fsck! Unplug the control unit and assume that its probably fried, judging from the amount of magic smoke escaping from the dash :/

Control unit is dead/questionable, purchase a replacement Order new unit, NOT CHEAP. The package really did arrive the next day! New unit exhibits similar issues. AC clutch is now switching on and off every few seconds. Decide to leave unit in dash but avoid AC functionality. All is well for a while. Driving down the road one day i smell a familar burning :/ Pull over to a parking lot and remove unit from dash in 5m flat. (I’m becoming an expert in this procedure!) We’re now approaching winter and i have no heat :\ Purchase vehicle subscription from ALLDATA. Scour through multiple service alerts relating to this issue. A bulletin i’d never noticed states that there can be shorts a) where the harness chafes against the ashtray b) behind the cassette deck. Next workday i pull out the cassette deck, detach the heater control wiring harness from a grey-white 6 pin mini harness which was located about 6 inches back from the AC control head connector.

This was a serious pain and scratched my hands and wrists raw. I pull the harness back through to the cassette deck area, peel back several feet of sticky electrical tape to find… 2 adjacent wires with missing insulation! One is attached by exactly 1 corroded strand of copper. Previous electrical tape repairs are present in the same area. The bracket for the cassette deck has sharp edges and is scraping 1mm of insulation from the harness. Taped up one slightly damaged wire, cut, joined and soldered the terribly burned wire back together. Applied electrical tape to cassette bracket edges and sealed up the entire harness with many layers of tape. I located yet another short in the wiring harness where it passes below the air filter and above the engine block on the passenger side. Seems that one of the wires had its insulation worn off . Repaired with more tape. Next i replaced the control unit for the second time, with a brand new part. It was sending crazy signals to the AC system;

opening doors, turning fans on and off. I can only assume that it was permanently damaged by prior shorts. Upon removal i notice that the unit smells badly like burned plastic. Lucky control unit #3 is installed in its place. The system now works, although the compressor is still being turned on and off in AC mode, albeit in a much quieter manner. Next i intend to disconnect the battery to clear the fault. I will also measure the system pressure to determine that i don’t have too much gas. The low pressure switch has been effectively disabled, and clutch wouldnt cycle at all with the switch connected, so perhaps there is too much pressure. GM bulletin(s) # 93-1B-129, #92-1-118 1991 Chevrolet Chevy K Pickup - 4WD LOW CHARGE INDICATOR FLASHES DISCONNECT CHARGE DETECTION #92-1-118 - (May 13, 1992) SUBJECT: A/C LOW CHARGE INDICATOR FLASHES (DISCONNECT LOW CHARGE DETECTION FEATURE) VEHICLES AFFECTED: 1991-1992 C/K TRUCKS WITH AIR CONDITIONING Some owners of 1991-1992 C/K vehicles may comment that the A/C letters in the middle of the control head face are flashing.

The HVAC control system used on 1991 and 1992 C/K vehicles incorporates a low A/C charge warning system. If a low charge is detected, the control head will not allow the compressor to engage and the A/C letters in the middle of the control head face that usually signify A/C operation will blink. The HVAC control head determines a low charge by monitoring the circuit from the pressure cycling switch. If the cycling switch will not allow the compressor to run more than 1.5 seconds, ten times in a row, the control head assumes a low charge and disables the compressor until reset. On some vehicles, it has been found that the wire from the pressure cycling switch to the control head is sensitive to EMI (electro magnetic interference) and gives false compressor cycling information to the HVAC control head which then disables the compressor. If you encounter a vehicle with the control head A/C indicator flashing the low charge signal but can find no reason for the flash using normal diagnostic procedures, including checking the wiring harness for chafing, remove the pressure cycling switch feedback wire from the control head connector.