Question about 2003 KTM 640 LC4 SM

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Pick up coil

Miss fire after 20/30 mins ride but open throttle rides through miss fire and clears checked every wire replaced spark plug and cap could be ignition pickups ?? stu thanks

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  • 127 Answers

That is a carburetor issue, possibly TPS, or lean midrange condition.

Posted on Apr 04, 2014


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Posted on Jan 02, 2017

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SOURCE: 2005 ktm 450 sx die while riding.

yes, you are correct, those are the two pieces that could solve your problem, but i would go first for your cdi, you may choose to have it tested first also, before you jump out to buy a new one.

Posted on Nov 24, 2008

  • 6966 Answers

SOURCE: new spark plugs last 10-15 minutes of riding

Hi and welcome to FixYa,

Offhand, the only factor to be checked that could foul a sparkplug for your bike would be the 2T oil injector/pump. There is too much 2T oil going to the combustion chamber. Either the injector would require restricting or for some reason, there is also 2T oil in the fuel tank (pre-mix).

Good luck and Thank you for using FixYa. Happy Holidays.

Posted on Dec 07, 2008

  • 12 Answers


Pull the plug back out of the cylinder and ground it against one of the head bolts, kick the engine over to see if you are getting a spark.

Posted on Jan 05, 2009

  • 4 Answers

SOURCE: 07 ktm 450sxf wont start

take your carb out, clean the entire thing, that means every nook in that *****. do this and if still a problem write back because in most cases were n idiot is involved, this is the most over looked problem

Posted on Feb 17, 2009

ollie reece
  • 1167 Answers

SOURCE: it started bogging down when riding and now it

hi buddy are you mixing it correctly with a mixing bottle with 40:1 ratio also on the carb will be a screw mixture screw turn this all the way in and unscrew it 1 1/2 turns out and try this also is there compression get back to me cf6410f.jpg

Posted on Sep 19, 2009

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Miss fire after up to temp and runfor short amount of time. I get a miss fire coming to a stop..drops to cylinders or 1. will not accelerate at all boggs with miss fire.

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Try replacing all four spark plug caps. The two straight caps unscrew off of the end of the wires. The other two are attached to the wire. You may not be able to order them from Honda any more. You can purchase bulk copper spark plug wire and replace the wires and the caps right out of the coils. You will need to purchase two straight 5000 OHM NGK brand plug caps and two long 90 degree NGK brand spark plugs caps. They should cost around $5 each. Copper core plug wire in bulk is about $2 a foot. Install some new plugs and there is a good chance the poor running will be solved for under$30.

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1982 GS850 Missing and Hesitation

fuel flow to cold pipe cylinder may be stopped with trash or sticky float.Resistor in plug wire for the one not firing could be bad. Try changing coil from one that is firing to the one thats not,see if that pipe gets hot or does the same thing still happen. coil ,plug wire, or fuel would be my primary focus.

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Number three cylinder is miss fire,it does not mean it is the coil,although it could be,remove the coil,and boot,and spark plug,inspect them to see if the plug,or boot look bad,replace the spark plug,and if the boot is burned or distorted,replace it,a fuel injector can cause a miss fire also,but change the spark plug and see if this solves the problem,if not replace the coil,if it is a dead miss,then the coil might be bad,as for the water in the fuel ,the cap is missing,,and 5 dollars worth of HEET will not hurt,also,fuel from the fuel station,can have water in it.It happens a lot.

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95 model thunderbird, runs great until idle, cuts out no spark bike starts again when it feels like it. when idling engine randomly miss fires as if you were flicking the kill switch on and off quickly....

The pick-up coils fail sometimes but usually lead to a complete failure
Before just replacing parts u can eliminate some suspects ie kill switch,clutch switch & ignition switch by bridging
Also check that there isnt a spark jumping from an HT lead or plug cap

Ride Safe

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