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Old 11-07-2003, 06:15 PM   #1
USArower
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My 96 AC EXT 580 efi will not start/run properly, but when you pull the rope, the pipe occasionally lets out a loud backfire. what causes this?
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Old 11-07-2003, 06:53 PM   #2
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You said it won't start/run properly, which is it??

if it runs, or turns over, and is getting spark then the exhaust is just loading up with fuel each time you pull the rope.

When it finally does spark then the unburned fuel in the exhaust system is ignited causing the backfire.


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Old 11-07-2003, 07:13 PM   #3
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put some new plugs...check if the old one are wet.
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Old 11-07-2003, 07:19 PM   #4
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sometimes it starts but doesn't run well. Most times it wont start.
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Old 11-07-2003, 07:43 PM   #5
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my snowmobile did that and found that it was just a dead plug. try new plugs and then try starting it with no choke, maybe ur really flooding it?
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Old 11-07-2003, 07:53 PM   #6
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I've seen those exact conditions when there was water in the gas.
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Old 11-07-2003, 08:14 PM   #7
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spark plug wires crossed???
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Old 11-07-2003, 09:37 PM   #8
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1)make sure the plugs are good 2) try and make shur you're not flooding it 3) take a gas sample by draining the carbs and put the gas in a clear jar and let sit for a couple of minutes, if you see a separation in the liquid there is probably water in the gas 4) put a timing light on the #1 cylinder and find your timing marks and have someone pull it over while you check the timing 5) undo the exhaust from the headpipe and make shur Mr. Mouse didn't build a nest in your exhaust, or that the pipe isn't carboned shut. But try to temporarily start the sled with the pipe undone but if it fires shut it off and check for exhaust restrictions 6) Unplug kill switch and see if it will start and run.(Most sleds will run with the kill switch unplugged) 7) last but not least if all else fails have the dealer check the coils and the stator......Hope these help but this is what I would do for checking out the problem.....Steve
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Old 11-07-2003, 10:46 PM   #9
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Sno-nuts has pretty much got it all said, but don't forget the basics. Check your compression, and do a spark test. If you've been firing it up and idling alot it may just be loaded with fuel.
Being an EFI model make sure any ground wires are clean and tight.
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Old 11-08-2003, 12:06 AM   #10
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I don't know alot about efi's, but my buddie's '95 wildcat 700 efi would act up if the battery was not fully charged.
Maybe an easy fix?
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