Nobody has any input?
Sportsman 400 loses spark
Hey guys, I have a 2005 Sportsman 400 that starts and runs for only a few min then dies. After maybe 5 min or so, it will start back up. At first I thought it was running out of fuel, But I have actually been able to remove plug wire quick enough to check spark, and it has none. After it sits a few min, it has spark. Put wire back on plug and it fires right up. I have Measured resistance across ignition coil, I get 12k ohms between plug cap and terminal on coil, and I get .3 ohms across terminals of coil. What wires come from the trigger? And what should I get for a reading there? Other suggestions? I know ecm's are common on these, and I have had bad coils that have actually tested fine. Thanks for your input!
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Regarding the wires from the trigger, they are typically located near the flywheel and send a signal to the ignition module or CDI box to trigger the spark. There are usually two wires, one for the trigger signal and one for ground. The trigger wire is typically marked with an "T" on the CDI box or ignition module.Hey guys, I have a 2005 Sportsman 400 that starts and runs for only a few min then dies. Tutuapp 9Apps Showbox After maybe 5 min or so, it will start back up. At first I thought it was running out of fuel, But I have actually been able to remove plug wire quick enough to check spark, and it has none. After it sits a few min, it has spark. Put wire back on plug and it fires right up. I have Measured resistance across ignition coil, I get 12k ohms between plug cap and terminal on coil, and I get .3 ohms across terminals of coil. What wires come from the trigger? And what should I get for a reading there? Other suggestions? I know ecm's are common on these, and I have had bad coils that have actually tested fine. Thanks for your input!
I did disconnect black wire and it made no difference. I have also checked resistance of the pick up both when it has no spark, and when it has spark. That reads 189 ohms each time. It is strange, it really acts like it is running out of fuel, but it has no spark when it dies. It will idle for a long time, but if you race it up it will die. Wait approx 5 min and starts right back up.First: disconnect the black (stop) wire from the CDI unit and try it
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I found them. Resistance checks out pretty close to spec, and resistance is same rather it will run or not.Regarding the wires from the trigger, they are typically located near the flywheel and send a signal to the ignition module or CDI box to trigger the spark. There are usually two wires, one for the trigger signal and one for ground. The trigger wire is typically marked with an "T" on the CDI box or ignition module.
Check the spark plug cap and coil resistance when cold and again when hot
I have Measured resistance at ignition coil, I get 12k ohms between plug cap and terminal on coil, and I get .3 ohms across terminals of coil. Is there any other test I can do to test for signal to coil? On cars we used to use a test light to check signal at coil, but that is showing my age.....Check the spark plug cap and coil resistance when cold and again when hot
Use a PEAK VOLTAGE METER to check the output of the pulse coil (3 to 5 volts peak typically) and CDI output to the coil (100 volts peak typically. If the meter is capable the output of the coil to the spark plug is typically 35,000 to 40,000 volts PEAK.
Thank you latebird. I appreciate your help. I have ordered a Peak Voltage Adapter through my supplier. I have been meaning to get one for a while now anyways.Use a PEAK VOLTAGE METER to check the output of the pulse coil (3 to 5 volts peak typically) and CDI output to the coil (100 volts peak typically. If the meter is capable the output of the coil to the spark plug is typically 35,000 to 40,000 volts PEAK.
Finally got back on this Sportsman. I have 4.3 volts on the pulse coil both when it has spark and when it does not. I went to check the CDI output to the coil and got a large arc when touching test lead from the Peak Volt Adapter. Is this supposed to happen? I have not tried again, i don't want to fry my meter.Thank you latebird. I appreciate your help. I have ordered a Peak Voltage Adapter through my supplier. I have been meaning to get one for a while now anyways.
You are supposed to connect the meter before cranking the engine - if the engine was not cranking, then the arc was caused by connecting the lead of the meter to the wire last - the meter should be connected to the wire first and then to ground - that should eliminate the arc or diminish it greatly - what was happening is the CDI capacitor was discharging into the PVA capacitor equalizing the potential between the two.
Engine was not cranking, key was not even on. I connected to the 2 wires coming from the CDI that go to the coil. So you are saying just connect test lead to the white and black wire, and other test lead dirrectly to engine ground? You know much more about this then me, so forgive the stupid question, but why does it matter if last connection is made to engine/chassie ground vrs the brown wire that goes to coil? I do understand ground side should be connected last.You are supposed to connect the meter before cranking the engine - if the engine was not cranking, then the arc was caused by connecting the lead of the meter to the wire last - the meter should be connected to the wire first and then to ground - that should eliminate the arc or diminish it greatly - what was happening is the CDI capacitor was discharging into the PVA capacitor equalizing the potential between the two.
It's entirely possible the CDI capacitor was fully charged and waiting for the signal to fire and either due to a faulty connection to the pulse coil or a faulty pulse coil or a faulty ground, never got the signal to discharge to the coil. It's also possible the coil is faulty or not grounded properly and the CDI had no path to ground to discharge to.
At any rate, it's not unusual to get an arc when connecting for testing and that is the reason for connecting to ground last when checking for voltage. When checking for continuity, it makes no difference when end is connected first
At any rate, it's not unusual to get an arc when connecting for testing and that is the reason for connecting to ground last when checking for voltage. When checking for continuity, it makes no difference when end is connected first
I feel like my PVA isnt working correctly, or i am not checking signal to ignition coil correctly. With ign coil disconnected and leads connected to w/blu and brown wires coming from CDI, engine cranking, i get 1.3volts and then voltage drops as it cranks. Back probing at ignition coil I get 4.6 volts cranking and 6.5 volts with engine running. (thought I was supposed to get close to 100volts peak) Again thanks for all your help! i am learning alot about this!It's entirely possible the CDI capacitor was fully charged and waiting for the signal to fire and either due to a faulty connection to the pulse coil or a faulty pulse coil or a faulty ground, never got the signal to discharge to the coil. It's also possible the coil is faulty or not grounded properly and the CDI had no path to ground to discharge to.
At any rate, it's not unusual to get an arc when connecting for testing and that is the reason for connecting to ground last when checking for voltage. When checking for continuity, it makes no difference when end is connected first
Voltage should increase with increase in rpm, but if you have a standard meter and a PV adapter, are you reading on the AC or DC scale? With a peak voltage function meter it can be read directly, but with a std meter and an adapter the reading should made on the DC scale.
I have it on the DC scale.Voltage should increase with increase in rpm, but if you have a standard meter and a PV adapter, are you reading on the AC or DC scale? With a peak voltage function meter it can be read directly, but with a std meter and an adapter the reading should made on the DC scale.
If it runs accept it and use your own multiplier until you have checked several different units and see what kind of readings you get. It's why I prefer the analog Simpson over my digital meters, but you will see variations between designs, that's why I say 'generally' - unless you have the manufacturer's specs on the system, you have to rely on acquired knowledge.
I am making a notebook with my readings. As I can't remember crap anymore. lolIf it runs accept it and use your own multiplier until you have checked several different units and see what kind of readings you get. It's why I prefer the analog Simpson over my digital meters, but you will see variations between designs, that's why I say 'generally' - unless you have the manufacturer's specs on the system, you have to rely on acquired knowledge.
I have now found that when this machine shuts off, the battery voltage is like 19 volts. Keep in mind this started out as an erratic engine dies after running for like 5min to 15 min. Now i can get it to die just by raising the rpms. So looks like my issue is a bad Voltage regulator?
Obviously high voltage can cause things to burn out or at a minimum overheat - yes fix the charging problem and reassess the ignition afterwards.
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