Troubleshooting Help: Front Cylinder not firing.

[rickdm]

Hello,

I have a 2013 ST Limited. It started running really rough. Extremely sluggish, no power. Sitting in neutral, I cannot get the RPMs above 5000 when revving, and it takes a bit to get to that even.

I have taken some of the plastics off, but haven't torn it completely down. I believe that it's only running on one cylinder.

Here's what I've done so far:
1. Disconnected the spark plug wire from the rear cylinder.
RESULT: Engine would not start.
2. Disconnected the spark plug wire for the front cylinder at the coil.
RESULT: Engine started and ran exactly like it has as described above.

So, with that said, I believe I have narrowed it down to the front cylinder not firing.
My question is, what should the next steps be?
Should I tear it down just enough to get to the front cylinder and check the plug condition?
New wires?
New coil?
Anything else that would cause this condition?

I have seen some discussions regarding plug wires, but I'm curious if anyone has ran into this same problem.

On another note, does anyone know if BRP is still offering the replacement side panels with better cooling? I bought this used.

Thanks for reading.

EDIT:
As I sit here and think about the issue this bike is having, here's a bit more information for symptoms.

As long as I have had the Spyder (about 2 years), it always ran rough when first starting. Clutch chatter would be a normal occurrence when starting out.
The engine would always run rough/low power until the RPMs would raise and then it would kick up and smooth out. Providing full power.

This makes me think that his has been an intermittent problem that is now no longer intermittent. Which would generally rule out a mechanical issue. They tend to not be intermittent. When something breaks, it usually breaks.

 

[Grandpot]

You seem to have a handle on what you are doing. Like you said, check the condition of the plug, then check to see if it is actually firing.

If the plug is firing, check the injector. You'll need to get a Node that will fit the injector plug. Do not apply 12V directly to the injector.

If the plug is firing and the Node indicates the injector is getting a firing signal, get a new injector.

If you do not have a Node, you can exchange the front injector with the rear and see if the problem switches to the other cylinder.

 

[GOZFST]

Be careful pulling the spark plug leads, if they are ungrounded it can damage the coils. Before you get too far into it, check the vacuum lines on the the throttle body. There are 2, one for each cylinder, the one in front seems to affected most by the trapped heat. They are easy to replace and fixed my rough running and stalling on my 2012 RT. Good luck. Do a search for the panels, if you can't find the BRP ones, one of the vendors here sells something similar

 

[rickdm]

You seem to have a handle on what you are doing. Like you said, check the condition of the plug, then check to see if it is actually firing.

If the plug is firing, check the injector. You'll need to get a Node that will fit the injector plug. Do not apply 12V directly to the injector.

If the plug is firing and the Node indicates the injector is getting a firing signal, get a new injector.

If you do not have a Node, you can exchange the front injector with the rear and see if the problem switches to the other cylinder.

Thanks Grandpot,

I really hope it's something simple. I do not have a node, but thanks for the tips.

Hopefully the injectors are (relatively) easy to get to.

 

[rickdm]

Be careful pulling the spark plug leads, if they are ungrounded it can damage the coils. Before you get too far into it, check the vacuum lines on the the throttle body. There are 2, one for each cylinder, the one in front seems to affected most by the trapped heat. They are easy to replace and fixed my rough running and stalling on my 2012 RT. Good luck. Do a search for the panels, if you can't find the BRP ones, one of the vendors here sells something similar

Thanks for the tips. I'll look into everything I can once I tear it down a bit more.

 

[Chupaca]

Little checking.....

I would get a plug wire and connect it to the coil with a spark plut at the other end grounded to the engine and crank the engine to see if you get spark to that plug. If you do the plug may be the issue and you will have to go in and change it. If so I recommend changing both plugs and get some high tension wires from BajaRon and be worry free. if no spark is present then it would be a coil or wiring to the coil issue. check all connection to the coil. The suggestion on the vaccum lines is good as many have had problems with them and replace them with silicone hoses. Also check the throttle body rubber manifolds for cracking. Sometimes spraying WD40 in that area will cause the rpm's to vary if they are leaking. Let us know what you find....:thumbup:

 

[rickdm]

I would get a plug wire and connect it to the coil with a spark plut at the other end grounded to the engine and crank the engine to see if you get spark to that plug. If you do the plug may be the issue and you will have to go in and change it. If so I recommend changing both plugs and get some high tension wires from BajaRon and be worry free. if no spark is present then it would be a coil or wiring to the coil issue. check all connection to the coil. The suggestion on the vaccum lines is good as many have had problems with them and replace them with silicone hoses. Also check the throttle body rubber manifolds for cracking. Sometimes spraying WD40 in that area will cause the rpm's to vary if they are leaking. Let us know what you find....:thumbup:

Thanks Chupaca,

I ordered new plugs and wires from BajaRon. Hopefully this weekend I'll get some time to start tearing into it. I'm planning on checking everything I can as I get access to it.
Here's to hoping it's a simple solution and not a Mechanical or Electronic issue.

 

[rickdm]

Problem Solved:

It was indeed a bad spark plug. New plugs and wires. What a pain in the ass for a simple spark plug change.

It runs so good now that I feel that it has never run right since I got it. Like a new ride. Checked the vacuum lines ans they look good. I'll change them at a later date since they are relatively easy to get to.

Thanks for the help and suggestions.

 

[Grandpot]

Good job.:clap:

 

[Haze]

Thanks for the followup.
I agree that changing the plugs on the ST is a difficult task but well worth the effort.
Good Job.