RS Warrior Forum banner

Front Cylinder Misfire

882 views 8 replies 3 participants last post by  arizonawarrior 
#1 ·
A little rundown:

-The front cylinder misfires at idle as well as under throttle.

-I can pull the female spades off the front coil and the bike will idle the same. It will start to sputter out under throttle though with the front spades out. If I pull the spades off the rear coil, the bike will almost immediately die at idle.

-I already replaced the front coil, both elbows, and both spark plugs. Figured one of these was the issue after the spade test, but alas nothing changed.

-This seemed to happen after riding through the rain, maybe it’s unrelated, maybe it’s not.

I’ve seen a few threads on this, but none that had a solid solution to their problem. Any help is appreciated!
 
#4 ·
First i would see which is the ground and check it for high resistance move wire and make sure you don't have break in the lead then go to the positive side and start with seeing if it's the same as the other coil. Another thing you might do is swap coils, if the problem moves with the coil you know it's the coil .
 
#5 ·
The stock coil's spark plug end 'boots' thread-into their cables. Gently rotate them clockwise and screw them all the way in but do not crush beyond bottoming-out.

Verify that your primary wires from the bike to the coils are correctly connected. The coils are not polarity sensitive but both sides should be similarly connected. Black-red wire goes to both coils use same connection location on coil. Black-orange goes ECU1 to rear (#1) jug. Black-white goes ECU2 to front (#2) jug.

Pull spark plugs and check both jugs to observe fuel and spark delivery, separate tests don't blow yourself up!

If none of these fixes it let us know.
 
#7 ·
Pull both spark plugs from the jugs. Shine a small flashlight into one hole and look in the other.

Truth is, with all the spark plugs out, the bike will not start so you can smell and listen for fuel. It will be obvious. But remove and set the spark plugs aside to avoid igniting fumes.

You can check spark separate by old-fashioned grounding or with an in-line test light to avoid pitting nice metal lol.
 
#8 ·
Checked spark on the front, both plugs are firing correctly. Did this through the diagnostic mode where it fires the coil 5 times, and had the spark plugs out to confirm a strong spark.

I’ll upload a pic of the plugs, as these are new with less than 10 miles on them.

It’s a PITA to take the whole air box off just to pull the plugs and check for fuel delivery, but that’s the only guess I have left. Maybe a clogged injector?

249565
 
#9 ·
Is that plug wet? If yes is it wet with fuel or wet with oil? The porcelain is completely black, is it dry carbon? Ten miles on a new plug it seems dark.

Also the ground electrode seems incorrectly bent. Did you check gap? What part number is marked on the plug?

Wondering, did you not check to see if fuel is spraying in that front jug while you had this spark plug out already? You could leave the plugs in the rear jug and pull just the plug wires off. Plus of course pull the plug wires off both front plugs so it would not ignite. Then remove even just one front plug (like you did already) and then turn the key on . . . and listen/smell while you crank it for a couple seconds.

You already visually verified its getting spark. Its strange the new plug looks so black if its not getting fuel too.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top