Here is the written procedure:
Closed Ignition: Primarily Pre-1998
A "Closed" ignition means the wiring needs to have a closed circuit in order to run. If the connection to any switch; key, kill, tether, throttle safety switch, etc.. is interrupted there will no longer be power to the ignition system and spark will cease. All Cats 1997 and earlier run a closed ignition, with the exception of the 1997 ZR 580 that is an open ignition.
Diagnosing no spark, weak spark or intermittent spark issues
First you want to see if it an issue in the switches/handlebars or if it is in the primary ignition components: stator, cdi, coils, trigger coil or possibly plugs, plug wires or plug caps.
1. First put the spark plugs in the spark plug boots and lay them on a cylinder head bolt so they are grounded. Make sure the plugs are not near the spark plug holes when you pull it over.
2. Pull the recoil rope checking the spark at the plug. Is there spark at each spark plug? Is the spark blue (indicating a strong spark) or is it yellow/orange (indicating a “weak” spark). If you have nice blue spark on one plug (if it is a twin) or two plugs (if it is a triple) and not the others, it may be as simple as having a bad/fouled out plug. Try replacing the non-sparking spark plug/plugs with new a new plug.
3. The next step is pretty much the same if you had no spark or a weak spark. On the “Closed” ignition you unplug the connector from the stator containing the yellow wires. This connector sends the power to the lights, hand warmers and tachometer. When you unplug this connector you need to put a jumper wire connecting the 2 “non yellow” wires together in the connector. This completes the electrical circuit which is needed to check for spark. I have a youtube video showing how to do this. By putting this jumper wire between the 2 non yellow wires you are bypassing all of your switches (Throttle Safety Switch, Kill, tether ect..) all of your lights and hand warmers ect..in your handlebars. Pull the recoil over and see if you have spark or if the previous yellow/orange weak spark is now blue. Carbureted models can be started and run with this 4-prong connector unplugged and the jumper wire in it but you won’t have lights ect..as mentioned before. If you have an EFI, you can only check for spark and it will not start or run with it unplugged. You need it plugged in to power your fuel pump. You can hook up a battery to the fuel pump and start it.
4. If by using the jumper wire you now have spark, there is something shorted out in your switches like the tether, throttle safety switch or kill switch. If you had weak spark and now have blue spark it also tells you that you have a short with one of your switches. Again likely culprits are the TSS, tether or kill switch. There is a 3 prong connector in your handlebars that if you unplug and jump the 2 outside prongs it will bypass your kill and TSS switch. Sometimes the TSS is 2 wire for instance the 2000ZR600 carb has 2 wires for the TSS connector. After bypassing these switches you will only be able to start and turn off your sled with the key. I have a video on youtube showing how to do this. The 3 prong connector is usually not by the thumb throttle but rather just a little bit down the steering shaft about at the point where the console containing the key switch is located. If you’re not sure which connector it is, just follow the group of wires from right handlebar area down to where the plug is located. There are a few other plugs by the handlebar on the right side by the thumb throttle, but they contain yellow wires and are for your hand warmers and thumb warmer. You also need to bypass the tether. You can just cut the wires in the back of the tether and splice the wires together which "completes" the circuit.
5. If after unplugging the 4-plug switch and using the jumper wire you still do not have spark or the spark continues to look weak this tells you that the problem is in the major ignition components like the stator, coils, cdi, spark plugs, spark plug wires or trigger coil.
6. The first thing to check is the connection from the stator to the cdi. Make sure all connections are free of moisture, are tight and use a little bit of dielectric grease on it. Check the ground. You should have a ground wire coming from your stator and your CDI/ECU box. Make sure the grounds are clean, tight and that the ground wires are not broken. Sometimes the ground wire is pinched and broken inside the eyelet connection and is making only intermittent if any connection. Some older model Arctic Cats have the ground up closer to the handle bars on what some would consider the “firewall” of the sled and they are notorious for rusting/corroding out badly.
7. If all connections are solid and the ground checks good then you start electrically checking components. Most twin trigger coils ohm specs are 90-100 or so ohms with new ones up to 115. Most triples are 175 ohms. I have a video on youtube showing how to check it. It is very easy and quick to test. The frustrating part about the trigger coil is that it can test good, but still be bad.
8. Next you want to test the stator itself. I have several videos for different models on youtube. I have 3 separate tests using the 3 main plugs used on carb and EFI 1990’s model stators.
9. If you continue to have no spark/weak spark and your trigger tests ok then we may be looking at a secondary coil issue. First you want to make sure the spark plug caps are on tight. They just screw on and off the spark plug wire. If your wires are long enough unscrew the spark plug caps, trim a ½ inch off the end of the wire and then screw the spark plug cap back on. Also, some spark plug wires unscrew from the coil itself. I had 2 sets of coils go “bad” on my sled. My triple coils showed 1 spark plug with extraordinary blue spark and the other 2 plugs were weak/yellow-ish in color. After I trimmed them and screwed them back together they ran perfect. Warn spark plug ends usually cause a miss or acts like a rev limiter. Be warned though that I did have one wire that would not unscrew from a coil and I ended up tearing the spark plug wire. Also, always check the spark plug gap and set it to the correct specifications.
10. If you have no spark and your trigger tests ok, your stator tests ok and you have trimmed the plug wires then we’re looking at a possible bad CDI box There is no real good way to test the CDI other than swapping the box out with a known good CDI box.
11. Specificly on Battery EFI sleds here is another thing to check. There can be a bad relay on the back of the ecu. There are 2 of them back there 1 for the spark and 1 for the fuel pump.
12. Also, bad reeds on a sled will cause it to back fire and run poorly acting like it is an electrical issue.
13. Lastly, if everything ohms out ok, tests ok, but you still don’t have spark or have a weak spark condition ect….you may want to take the stator out of the sled or put the snowmobile in a warm room if your stator ohms are a little on the low side. I have seen stators that ohms out at 430 and 44 in the cold, but when you bring them up to room temp (50-70 degrees F), one of the ignition coils will measure higher than it is supposed to. On a 450 & 45 ohm stator for instance; if the low speed coil measures 455 when it is at 50-70 degrees F, then it is bad. If the 45ohm high speed coil is at 48 ohms when tested at 50-70 degrees F, then it is bad. If an OEM stator ever measures higher than the specs given, it is bad. I have seen several measure anywhere from 420-440 when cold but only after they were warmed up to 50-70 degrees F did their stator ohms actually measure higher and reveal that the stator was actually bad.