engine will not idle, seems as though it's running on 1 cyl.

[V-FORE]

Hi all I am trying to figure out my problem, I just read fuzzys thread on his fuel pump. A little history, bought my NC700X new 10/28/12, she is my commuter right now she has a little over 32k on her. The problem started the other morning on the way to work. She seemed down on power and will not idle I have to keep the rpms up. I just changed the plugs & air filter for the 1st time...air filter was fine, plugs looked like it has been running quite rich. I checked spark on both new plugs, it was good. Fired her up and it seems to run at less than 100% so I decide to wait a day and check the valves tonight for kicks. I did a compression check 155 & 160#s which seems fine. I will verify that both cylinders are working after I check the valves. Has anyone else had any problems like this ? There is no faults on the idiot lights and my thoughts are that most likely one of the injectors is plugged. Any input would be appreciated. I will be checking back as possible and update with any findings.

Gary

 

[Saturday Morning]

From your description, it does sound like it may have a bad injector. See If you can get it to run at a fast idle by having someone hold the throttle and then individually pull the plug wires (one at a time) to find the dead cyl. If the bike consistently stalls when the one plug wire is pulled but has no change when the other is pulled would be a tell-tell sign.

-Saturday

 

[Old Can Ride]

Most times but not always, unless you hear the valves clatter it is not the valves. See if a spark plug wire came loose at the coil when you changed the plugs. Try changing plugs with new plugs if too rich or lean. If all still does not work try unplugging electric plugins using dielectric or electronic clear on electric fittings when you put the electric fittings back together. Did you get a MIL code?

 

[itlives]

If the symptoms started right after the work you did, it's something you did. I don't really know how the injectors work but I'm thinking it's a ground issue somewhere. OCR has a point about the plugs, also.

 

[V-FORE]

I managed to squeeze out a little time to work on her last night. Her problem is running overly rich, that is why she keeps stalling out and is way down on power, I was running it and disconnecting the plugs to verify that both cyls are firing and they are. I disconnected the battery and waited, then started back up and no change. I think that I am now over my head. Time to run her into the shop so they can tell me what is causing the injectors to keep dumping fuel in....

 

[Brillot2000]

If it were the fuel pump, the bike would not start at all, that's if the failure is absolute. An intermittent one would be a different story, you'd experience engine surging while on the throttle at random instances.

Injectors can fail, either they do not work, which is the usual mode of failure or they could in theory not close entirely and leak fuel into the combustion chamber when not needed. Another thing could be the O2 sensor.

Either way, it's best to take to someone that can read the Trouble Codes from the ECU. Is the MIL (Malfunction Indicator Light) or Check Engine Light currently on?

Dealers have a diagnostic tool that can read "Live Data" from the ECU. This will help them find the issue in a few minutes of reviewing the parameters being displayed. You will drive yourself nuts trying to figure out this issue...

 

[V-FORE]

Thank you for the info Bruce, I am a bit of a dinosaur when it comes to motors I am unable to grasp all the different sensors and such, all you need is Fuel, Air & Spark....and I have all three just not in the correct proportion. : ) I am glad that nowadays they have tools that tell you what the problem is, I am just stuck with my troubleshooting experience....

Gary

 

[L.B.S.]

Thank you for the info Bruce, I am a bit of a dinosaur when it comes to motors I am unable to grasp all the different sensors and such, all you need is Fuel, Air & Spark....and I have all three just not in the correct proportion. : ) I am glad that nowadays they have tools that tell you what the problem is, I am just stuck with my troubleshooting experience....

Gary

Sorry I can't be of any help guessing what the problem is, but I've got my fingers crossed for ya that it's a simple thing (and cheap, lol)

Please let us know what the result is once sussed out!

 

[lootzyan]

... I did a compression check 155 & 160#s which seems fine...

Cylinder compression should be:
at 470 RPM - 1,775 kPa (18.1 kgf/cm 2 , 257 psi). (SM p. 1-9)
Maybe you should check it again, if you have a right tool.

 

[kharli]

A poor electrical connection or low voltage from battery can set the bike in safe mode and make the bike sound really rough.

 

[Saturday Morning]

Just following up out of curiosity.. Problem solved? Back on the road?

 

[V-FORE]

No answer yet, dropped it off at the Honda dealer yesterday afternoon. As soon as I find out what they come up with I will update and let all know.

Thanks for the reminder!

 

[Jguarfn28]

Check the coil and make sure that connection is complete. I had a Suzuki GS500 that vibrated off a connector to one spark plug there and I was intermittently running on one cylinder.

 

[V-FORE]

Well I heard back from the shop today, I was told that it was the cam gear, cam chain & tensioner I will know the full details when I pick it up. Parts are on order and Honda is taking care of it! As soon as I know the full details I will update this. When the shop called me last week,*I came up with the idea that it might have slipped a tooth, that made sense since there were no error codes.... Looking forward to being back on two wheels!!