SX Viper misfire

R

ringolake

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Aug 19, 2008
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Long story shortened, my friend bought a really nice 2002 Viper. Within the first mile it warped the mag piston which took out the crank. Whoever summerized it pulled the carbs out of their rubber boots and didn't get the mag carb back in. You couldn't see this from the top. Now the motors all back together but the mechanic said the stator was faulty and had to replace it. That was replaced yesterday. Now it misfires up and until you get the rpms over 3,500, then it runs correctly. The TORS has been overridden but doesn't help. Any ideas on this apparent electrical issue would be much appreciated. He paid $2,000 and now has that in repairs. The mechanic is as honest as they get.
 
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Does it backfire and pop or just bog until up over 3500 rpm?
If it is bogging, does blipping the choke on/off help?
 
This is what he's saying: It bogs more than backfire but it acts like it's loosing ignition I don't think it's the carbs because you said it ran fine before". He says now he can "pick it up with the choke".
 
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That's what I thought. He's going to clean the carbs tonight. He also mentioned the reeds, but said they looked good when he reinstalled. Thanks
 
Cleaned the carbs and found nothing. Checked for air leaks and nothing. It runs great on top but won't idle much below 3,000.
 
Define "cleaned the carbs".
Did you remove the pilot jets and just spray carb cleaner through them and put back in? OR, did you hold them up to a light and make sure you could see a well defined ROUND hole through them? Many times you have to run a small wire through them to actually get the crud out. Also need to take the fuel screws clear out and spray cleaner through the pilot jet opening so that it comes out the fuel screw opening.
Also, what are fuel screws being set at?
If the choke helps it, then it is either lacking fuel on the pilot circuit or it is sucking air somewhere. I'd imagine it is tough to check for an air leak by spraying around the boots since it won't idle.
 
Ok, I went and drove it tonight. He had the idle set at 2,000 because under that it would kill. It ran fine above that but seemed flat. It's 35° and high humidity. Then he pulled out a tool to check spark and it turns out it loses spark on cylinders 1 and 3 under about 1,900 rpm! The middle cylinder keeps spark. I'm hoping you guys can tell me what's going on. Thank you
 
I should also state that he just replaced the stator because it was bad. And that it ran down to 2,000 rpm now after he cleaned the carbs.
 
Turns out it was what my freind calls the igniter coil that's attached to the stator. He cut the one off the bad OEM part and swapped it on the new aftermarket part. Now it has spark across the cylinders and idles at 1,400 rpm. So, it was a bad Chinese made coil. It'll be interesting to see how long it holds up pieced together like that. Thanks guys for your input.
 
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