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|02-14-2010, 10:15 PM||#1 (permalink)|
Join Date: Jan 2010
hi i have a 98 zr 600 efi. I bought it with a bad stator, so i put one in got it running. I took it out for a ride and it started to backfire and bog down at low speeds, esspacialy after having it WOT. and after ridding down the trail at half throttle, come to a road, stop and falls on its face and backfires. Dont no why its doing it hoping someone can help me out thanks.
|02-15-2010, 07:11 AM||#2 (permalink)|
Super Advanced Member
Join Date: Apr 2003
Current Sled(s): Ron Hunyady 1107 Cat Triple & Stock 1000
Location: Flushing, MI
Riding Since: 1986
Here is a spark diagnositc to go through. Could be any of these things from bad reed to bad stator to the TSS switch ect...could be a lot of different things causing your issue:
Open Ignition: 1998 and newer ZR’s and ZL’s 1998-2002 ZRT 600,800 and 1000
With open ignitions a live wire goes from the ignition system to all of the switches. The switches are normally open, or not making connection, until in the "OFF" position. When in the "OFF" position the switch will ground the ignition wire to the chassis effectively killing the spark. If a connecter becomes 100% disconnected or if a wire gets cut then the switch will no longer turn off the engine but the engine will still start and run. With the "normally closed" system if a connector comes loose or a wire gets cut the spark will stop until the wiring is repaired completing the circuit again.
Diagnosing no spark, weak spark or intermittent spark issues
First is separating the issue between switches/handlebars/lights or if the issue is in the primary ignition components like the stator, cdi, coils, trigger coil or possibly plugs or plug wires or plug caps.
1. First thread the spark plugs out of the cylinder heads, put the spark plugs in the spark plug boots and lay them on the cylinder head bolt away from the cylinder plug hole so they are grounded. If you pull the sled over and the spark plug is over the spark plug hole and it sparks it will ignite so make sure the plugs are not near the spark plug holes when you pull it over
2. Pull the recoil rope and check the spark at the plug. Is there spark? Is there spark at each spark plug? Is the spark blue (indicating a strong spark) or is it yellow (indicating a “weak” spark). If you have nice blue spark on one plug 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 or spark plugs (on a triple) with new spark plugs.
3. The next step is pretty much the same whether you saw no spark or a weak spark. On the “open” ignition you can simply unplug the 4-prong connector coming from the stator containing the 2 yellow wires. On some EFI sleds you have 3 yellow wires and one non yellow (ground) wire. The extra yellow wire is used for powering your fuel pump. The other 2 yellow wires in the 4-prong connector sends the power to the lights/hand warmers/tachometer. When you unplug this 4-prong connector you are bypassing all of your switches (Throttle Safety Switch, Kill, Tether ect..) and all of your lights, hand warmers ect..in your handlebars. Pull the recoil over and see if you have spark or if the spark is now blue. Carbureted models can be started and run with this 4-prong connector unplugged but you won’t have lights ect..as mentioned above. 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 run a battery to the fuel pump with it unplugged and it can/will start and run.
4. If you had no spark and by unplugging the 4-prong connector you now have spark, that tells you that you have something shorted out in your hand controls, 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 or a problem with one of your switches. The most likely culprit is the TSS or kill switch, There is a 3 prong connector in your handlebars that if you unplug it will bypass your kill and TSS switch and you will only be able to start and turn off your sled with the key. The 3 prong connector is not by your 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 one group of wires out of the right handlebar area where the TSS and Kill switch are located down to where the plug is located. There are other plugs in the handlebar area by the right side by the thumb throttle containing yellow wires. They are for your hand warmers/thumb warmer and have nothing to do with the TSS or kill switch.
5. If after unplugging the 4-plug connector there is no spark or the spark still looks 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. First check the connections from the stator to the cdi. Make sure all connections are free of moisture, tight and use a small amount of dielectric grease. Check the ground. You have a ground wire coming from your stator and your CDI/ECU box. Make sure the ground is clean, tight and that the ground wires are not broken/loose. 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 is considered the “firewall” of the sled and they rust/corrode badly.
7. If all connections are solid and the ground looks good then you start electrically checking components. Most twin trigger coils ohm specs are 90 or so ohms. Triples are usually 175 ohms. View my “testing a pulser/trigger coil” video to see how to test it. It is a quick/easy ohm test. The frustrating part about the trigger coil is that it can test good, but still be bad.
8. Next test the stator itself. View my “How to test a stator” video to see how to do it. Triple cats and ZR/ZL 500/600 carb sleds have the 4 prong connector. The ZR/ZL 500/600/580 EFI’s have the clear 3 prong rectangular plug and many of the 580/700 carbs have a triangular plug.
9. If you have no spark and your trigger tests ok and your stator tests ok then we may be looking at a secondary coil issue. The coils can have a couple of issues with them. The first thing you want to do is make sure the spark plug caps are on tight and clean. They just screw on and off the spark plug wire. If your wires are long enough unscrew the spark plug caps, trim a ˝ inch off the end of the wire and then screw the spark plug cap back on. Also, on some coils you can unscrew the wire from the coil itself and do the same thing. I had 2 sets of coils go “bad” on my sled and come to find out it was just the spark plug wires were a bit warn at the spark plug end and after I trimmed them and screwed them back together they ran perfect. Be warned though that I did have one wire that would not unscrew from a coil that was supposed to no matter how hard I tried to turn it and I ended up tearing the spark plug wire. Also, always check the spark plug gap and set it to the correct specs. I have seen plugs with the gap set too small on them making the motor run poorly.
As far as putting the coil wires back on which cylinder here is a general rule of thumb for Cats:
Most sleds fire all the plugs at the same time, multiple times per revolution. A twin will fire both wires twice each revolution, a triple three times (once per 120 degrees). One of the pulses fires the plug to ignite the fuel/air mix, the other times the pulses are "lost" as the plug fires with the piston not ready for the fuel to burn.
10. If you have no spark and your trigger tests ok, your stator tests ok and you have tried a new set of coils then we’re possibly looking at a 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. This was found on a 1996 EXT EFI: There are 2 relays on the back of the ecu. 1 is for the spark and 1 for the fuel pump.
12. Bad reeds on a sled will cause it to back fire and run poorly acting like it is an electrical issue.
13. Sled won’t shut off condition: I have seen a few things cause this. It is usually a bad ground/broken ground wire. Sometimes it is moisture in the connector. I had to disconnect my TSS/Kill switch the day my kill switch got moisture in it and my sled wouldn’t shut off. You could have a cdi with an internal short. Also, a bad stator can cause a sled to not shut off.
14. Other issues/symptoms that I have seen/read related to a no spark/Weak Spark/Wet Plugs issue:
A. A guy bought a used sled with the wrong flywheel on it.
B. Frayed wires somewhere in the wiring harness or under the seat were causing a short
C. Sled was only running on one cylinder. He could remove one spark plug wire and it didn’t effect the way the sled ran. His low side coil on his stator read 360 ohms and it should have measured 450 ohms. His low side coil was dying.
D. It kept fowling plugs left and right. The guy before me ran ethanol, and never told me. This was on an EFI sled.
E. Hood harness was routed between rewind/stator housing and frame and had 4 wires smashed. Repaired wires and ran good.
F. Got it running again tapped the ECU and died. Pulled the ECU cover off and found some corrosion
G. Wires running to the carbs were rubbing against the jack shaft (Shaft going from secondary clutch to the top sprocket in the chain case). After rewrapping/rerouting the wires it ran great
H. Bolt for the recoil cup broke off and hit the trigger coil, bent the bracket slightly and gave it too much air gap
I. Oil Injection turned up too high
J. Fuel Lines hooked up backwards
K. Lean jetting will cause a bog. The sled would start and idle but if you pinned the throttle the sled would bog and quit running. By using the choke we were able to determine that it ran better when you hit the throttle. We jetted up and it ran good.
L. Sheared Timing key
M. Crank out of Phase will cause it to run very poorly.
N. Too much dielectric grease in the trigger connector caused sled to bog.
Wanted: Dead 1990's era Stators and CDI boxes
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The link below leads you to my Cat electrical diagnosis videos.
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