Another chinese no spark
#1
01-07-2012, 10:33 AM
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Another chinese no spark
My kids have a 110cc 4 stroke chinese gokart that just quit while they were riding it. I checked for spark and it has none. I have replaced the plug and the cdi.
I have checked the voltages and resistance at the 5 pin cdi which looks exactly like the one for atvs.
On the kill switch pin of the cdi connector I get infinite ohms
machine has one kill switch on dash
AC ignition power pin I get 46Vac the resistance from this winding to ground is 336 ohms
timing trigger pin to engine ground is .166 Vac, resistance to ground is 113 ohms
ground pin to engine ground = continuity
The resistance of primary and secondary coils are = continuity
I am at a loss to figure this thing out and any help would be really appreciated.
I have checked the voltages and resistance at the 5 pin cdi which looks exactly like the one for atvs.
On the kill switch pin of the cdi connector I get infinite ohms
machine has one kill switch on dash
AC ignition power pin I get 46Vac the resistance from this winding to ground is 336 ohms
timing trigger pin to engine ground is .166 Vac, resistance to ground is 113 ohms
ground pin to engine ground = continuity
The resistance of primary and secondary coils are = continuity
I am at a loss to figure this thing out and any help would be really appreciated.
#2
01-07-2012, 11:00 PM
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#3
01-08-2012, 02:00 AM
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My responses in blue...
Here is the generic procedure:
My kids have a 110cc 4 stroke chinese gokart that just quit while they were riding it. I checked for spark and it has none. I have replaced the plug and the cdi.
I have checked the voltages and resistance at the 5 pin cdi which looks exactly like the one for atvs.
On the kill switch pin of the cdi connector I get infinite ohms [OK]
machine has one kill switch on dash
AC ignition power pin I get 46Vac the resistance from this winding to ground is 336 ohms [OK]
timing trigger pin to engine ground is .166 Vac, resistance to ground is 113 ohms [This is a little low, but it may be just your meter. Or maybe not. Look at the generic procedure posted below and pay particular attention to the ignition coil primary voltages with the CDI hooked up. What we need to see is whether the CDI is being triggered or not. And that means seeing some voltage pulses here or not.]
ground pin to engine ground = continuity
The resistance of primary and secondary coils are = continuity
I am at a loss to figure this thing out and any help would be really appreciated.
I have checked the voltages and resistance at the 5 pin cdi which looks exactly like the one for atvs.
On the kill switch pin of the cdi connector I get infinite ohms [OK]
machine has one kill switch on dash
AC ignition power pin I get 46Vac the resistance from this winding to ground is 336 ohms [OK]
timing trigger pin to engine ground is .166 Vac, resistance to ground is 113 ohms [This is a little low, but it may be just your meter. Or maybe not. Look at the generic procedure posted below and pay particular attention to the ignition coil primary voltages with the CDI hooked up. What we need to see is whether the CDI is being triggered or not. And that means seeing some voltage pulses here or not.]
ground pin to engine ground = continuity
The resistance of primary and secondary coils are = continuity
I am at a loss to figure this thing out and any help would be really appreciated.
Is this a picture of your CDI?
Assuming the answer is yes, the first thing to do is eliminate all kill switches and kill switch wiring:
Method 1) Unplug the CDI and remove the kill switch pin in the CDI connector on the wiring harness. The pin is held in with a spring tab on the pin itself. You'll have to probe into the connector and push this tab in order to extract the pin. Plug the CDI back in (kill switch wire dangling) and see if you have spark.
Method 2) Unplug the CDI. Turn on the ignition switch and set all kill switches to the run position. Use a meter to measure resistance in of the kill switch pin in the wiring harness connector to engine/frame ground. If the reistance is infinite on the 100K ohm scale then your kill switches/kill switch wiring are OK. If you measure zero ohms then you have a kill switch/wiring issue.
The other inputs your CDI needs to make spark are AC Ignition Power, and the Trigger signal. Do the following:
1) Unplug the CDI. In the wiring connector measure the resistance of the AC Ignition Power pin to the Ground pin. You should see 400 ohms or so. What do you measure?
2) Measure the resistance of the Timing/trigger pin to the ground pin. You should measure 150 ohms or so. What do you measure?
3) Leave the CDI unplugged. Set your meter to measure AC volts on the 100 volt scale. Measure the voltage on the AC Ignition Power pin to the ground pin while cranking the engine. You should see 40 to 80 volts AC while the engine is cranking. What do you measure?
4) Set your meter to measure AC volts on the lowest scale you have. Ideally this would be 2 volts but many meters don't go down this low. In that case use the lowest scale you have. Measure the voltage on the Timing Trigger pin to the Ground pin while cranking the engine. You should 0.2 t0 0.4 volts AC. What do you measure?
Now for measuring the output side of the CDI:
A) Leave the CDI unplugged. In the CDI wiring connector measure the resistance of the Ignition Coil pin to the ground pin. You should measure less than 1 ohm (but not zero ohms). What do you measure?
B) Plug the CDI back in. Set your meter to measure AC volts on the 20 volt scale. Set all kill switches to the run position. Crank the engine while measuring the voltage on the Igntition Coil pin to ground. Poke through the insulation of the wire if you can't probe the connector.
Caution: There should be moderately high voltage spikes on this wire. Make sure your fingers are not part of the circuitry. Don't touch the probe lead tips while doing this test.
What you should see is a lot of random numbers with lots of zero values as well. This is because the meter may catch all or part of the spark event voltage, with a lot of nothing in between. Describe what you see.
Note: Using a meter to measure this point produces highly variable results depending on the meter. What you really need is an oscilloscope, but most always a meter is all that is available. We have to do the best we can with what's available. Describe the meter results as accurately as you can - there is information there to chew on....
Assuming the answer is yes, the first thing to do is eliminate all kill switches and kill switch wiring:
Method 1) Unplug the CDI and remove the kill switch pin in the CDI connector on the wiring harness. The pin is held in with a spring tab on the pin itself. You'll have to probe into the connector and push this tab in order to extract the pin. Plug the CDI back in (kill switch wire dangling) and see if you have spark.
Method 2) Unplug the CDI. Turn on the ignition switch and set all kill switches to the run position. Use a meter to measure resistance in of the kill switch pin in the wiring harness connector to engine/frame ground. If the reistance is infinite on the 100K ohm scale then your kill switches/kill switch wiring are OK. If you measure zero ohms then you have a kill switch/wiring issue.
The other inputs your CDI needs to make spark are AC Ignition Power, and the Trigger signal. Do the following:
1) Unplug the CDI. In the wiring connector measure the resistance of the AC Ignition Power pin to the Ground pin. You should see 400 ohms or so. What do you measure?
2) Measure the resistance of the Timing/trigger pin to the ground pin. You should measure 150 ohms or so. What do you measure?
3) Leave the CDI unplugged. Set your meter to measure AC volts on the 100 volt scale. Measure the voltage on the AC Ignition Power pin to the ground pin while cranking the engine. You should see 40 to 80 volts AC while the engine is cranking. What do you measure?
4) Set your meter to measure AC volts on the lowest scale you have. Ideally this would be 2 volts but many meters don't go down this low. In that case use the lowest scale you have. Measure the voltage on the Timing Trigger pin to the Ground pin while cranking the engine. You should 0.2 t0 0.4 volts AC. What do you measure?
Now for measuring the output side of the CDI:
A) Leave the CDI unplugged. In the CDI wiring connector measure the resistance of the Ignition Coil pin to the ground pin. You should measure less than 1 ohm (but not zero ohms). What do you measure?
B) Plug the CDI back in. Set your meter to measure AC volts on the 20 volt scale. Set all kill switches to the run position. Crank the engine while measuring the voltage on the Igntition Coil pin to ground. Poke through the insulation of the wire if you can't probe the connector.
Caution: There should be moderately high voltage spikes on this wire. Make sure your fingers are not part of the circuitry. Don't touch the probe lead tips while doing this test.
What you should see is a lot of random numbers with lots of zero values as well. This is because the meter may catch all or part of the spark event voltage, with a lot of nothing in between. Describe what you see.
Note: Using a meter to measure this point produces highly variable results depending on the meter. What you really need is an oscilloscope, but most always a meter is all that is available. We have to do the best we can with what's available. Describe the meter results as accurately as you can - there is information there to chew on....
#4
01-08-2012, 02:12 AM
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The purpose of the resistor is to limit radio frequency interference being emitted from the quad
#5
01-08-2012, 01:00 PM
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Lynn, first I would like to say many thanks for the help.
I tried all suggested measurements using another meter, both meters are auto ranging, and came up with similar results.
AC ignition power pin to ground =341ohms
Timing/trigger pin to ground pin =117ohms
cdi unplugged:
AC ignition power pin to ground pin while cranking =45 Vac
Timing trigger pin to ground pin while cranking=.165Vac
ignition coil pin to ground =3ohm
cdi plugged:
ignition pin to ground=3ohm
ignition coil pin to ground while cranking=.020Vac which was pretty steady and maybe fluctuated between .017 and .020Vac
I also checked the primary and secondary coil resistance and got
.7ohms and 9.7k ohms respectively.
These measurements were taken with a new cdi but I know sometimes new parts can be bad.
I tried all suggested measurements using another meter, both meters are auto ranging, and came up with similar results.
AC ignition power pin to ground =341ohms
Timing/trigger pin to ground pin =117ohms
cdi unplugged:
AC ignition power pin to ground pin while cranking =45 Vac
Timing trigger pin to ground pin while cranking=.165Vac
ignition coil pin to ground =3ohm
cdi plugged:
ignition pin to ground=3ohm
ignition coil pin to ground while cranking=.020Vac which was pretty steady and maybe fluctuated between .017 and .020Vac
I also checked the primary and secondary coil resistance and got
.7ohms and 9.7k ohms respectively.
These measurements were taken with a new cdi but I know sometimes new parts can be bad.
#6
01-08-2012, 10:52 PM
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Lynn, first I would like to say many thanks for the help.
I tried all suggested measurements using another meter, both meters are auto ranging, and came up with similar results.
AC ignition power pin to ground =341ohms
Timing/trigger pin to ground pin =117ohms
cdi unplugged:
AC ignition power pin to ground pin while cranking =45 Vac
Timing trigger pin to ground pin while cranking=.165Vac
ignition coil pin to ground =3ohm
cdi plugged:
ignition pin to ground=3ohm
ignition coil pin to ground while cranking=.020Vac which was pretty steady and maybe fluctuated between .017 and .020Vac
I also checked the primary and secondary coil resistance and got
.7ohms and 9.7k ohms respectively.
These measurements were taken with a new cdi but I know sometimes new parts can be bad.
I tried all suggested measurements using another meter, both meters are auto ranging, and came up with similar results.
AC ignition power pin to ground =341ohms
Timing/trigger pin to ground pin =117ohms
cdi unplugged:
AC ignition power pin to ground pin while cranking =45 Vac
Timing trigger pin to ground pin while cranking=.165Vac
ignition coil pin to ground =3ohm
cdi plugged:
ignition pin to ground=3ohm
ignition coil pin to ground while cranking=.020Vac which was pretty steady and maybe fluctuated between .017 and .020Vac
I also checked the primary and secondary coil resistance and got
.7ohms and 9.7k ohms respectively.
These measurements were taken with a new cdi but I know sometimes new parts can be bad.
Your ignition coil voltages from the CDI suggest that the CDI internal storage capacitor is being charged through the coil primary winding, but the CDI is never being triggered. This could be due to a lack of trigger signal to the CDI, or a fault within the CDI.
The 0.165 volts trigger signal on two meters suggest that the CDI is getting a sufficient trigger signal, so this points to a bad CDI.
If it were me I would put the old CDI back in and redo the ignition coil voltage tests. Maybe you have two bad CDIs in a row, or maybe you had another problem and have now added a bad new CDI into the mix. My thinking is this: Two good CDIs should work the same. A bad CDI has many failure modes with different symptoms being expressed. If the two CDI's act differently then one or both is probably bad. We can analyze the differences and maybe get more clues as to what is going on...
#7
01-10-2012, 05:42 PM
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I checked the ignition coil pin to ground while cranking on the old cdi and got similar results though I did see the meter go to .040 Vac one time, but it was mostly in the .017-.020 range.
I also checked again for spark and there was none. What do you think I should do next? Gas and a match
I also checked again for spark and there was none. What do you think I should do next? Gas and a match
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#8
01-11-2012, 10:35 PM
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This is a case where all the measurements are in, seem to be consistent, and are not completely conclusive. So we're left with playing the odds. I think that 0.166 volts AC for the trigger is a little low but sufficient to trigger the CDI, yet the CDI is acting like it is not being triggered. Thus I would say that the most likely scenario is that both CDIs are bad. I would try another CDI from a different vendor. Remember that CDIs are made in batches, and also ordered from/shipped to your vendor in batches. Your vendor may have a lot of additional bad CDIs, so by buying from a different source you improve your odds of getting a CDI from a different batch or even a different manufacturer source.
Another reason to try the CDI first is that it is cheaper and easier to change than the stator.
Another reason to try the CDI first is that it is cheaper and easier to change than the stator
.
#9
01-12-2012, 07:54 AM
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#10
01-25-2012, 12:11 PM
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