Engine stalls at low RPM ?

[Fisherdave]

Let me apologize in advance if this topic has been covered & I missed it.

I have encountered a problem with my bike stalling at low RPM. This is particularly evident when I shut down the throttle & then open it again. It usually occurs when I'm coming up to a stop sign & am shifting down. Sometimes the bike will stall out completely when I pull in the clutch to stop. Other times it will stall when I am taking off from a stop sign. It is also evident at around 3K RPM in either 4th or 5th gear. It tends to want to stall out. I have to pull in the clutch & give it some revs.

I have taken the bike to the dealer & have had the spark plug ends replaced as indicated in the service bulletin. That did not help.

At one point I had a dash light come on that indicated a fuel injection issue. The dealer did a diagnostic & then replaced the MAP sensor (under the emissions warranty 5 years 18K miles).

I got the bike back last week & the problem continues. An interesting side note, however, is that when I add some gas additive (STP Fuel Dry) it seems to run just fine. I did this originally because I thought I may have gotten some bad gas. Although this is a possibility, I have my doubts that I could have gotten 6 tanks of bad gas.

The bike is a 2010 w/about 14K miles on it.

Any thoughts, theories, wisdom, etc. will be greatly appreciated.

 

[skatefriday]

I'm close to buying a new leftover 2010 NT from a dealer. Is this something I need to worry about?

 

[Fisherdave]

This is my favorite motorcycle & I have had them since 1969. I hope my problem is an isolated case. I don't think I'd be put off from buying an NT700V.

 

[Phil Tarman]

I'm close to buying a new leftover 2010 NT from a dealer. Is this something I need to worry about?

I don't think so. It seems to be pretty rare. We don't hear much of it here and I didn't see much reference to it on the UK Deauville site when I hung out there.

 

[skatefriday]

Sorry, I was specifically referring to bad gas. Should I ask the dealer to drain the tank and is there any long term damage that can happen from gas just sitting for two years?

 

[Lorien]

Sorry, I was specifically referring to bad gas. Should I ask the dealer to drain the tank and is there any long term damage that can happen from gas just sitting for two years?

Maybe and maybe. My first thought was to say yes and yes but that may be a little severe. I would be far more comfortable if the bike did have the fuel system purged of old fuel. Now you might get reassurances that it has been run weekly and fuel additive put in the tank to keep the water out but a fresh tank of gas and say a hundred miles in a day on the new gas would make me feel better about these issues.

Oh and while I am at it. I can imagine that residual water in the tank might cause the problem that started the thread but unless you have a very significant water contamination a good dose of Sta-Bil or something like it should be a fix unless your routine fuel supplier has bad gas all the time.

 

[1fastbob]

My question would be....how much gas have you ran through it with it running poorly? Also, if you buy your gas at the same place frequently, try buying gas at a different location.

Too much water causes problems with E-10, but water also causes problems with plain old gasoline.

 

[karl]

Dry Gas is alcohol... so just add fresh E19 for the same effect.

 

[Rob]

funny - my roommate once took my NT for a spin and told me later he stalled it at 30mph. i have no idea how that's even possible. i can only assume he bogged the engine down to cause this. i never had the NT stall on me, but i also never tried to ride it at 1600 rpm, either.

 

[Fisherdave]

I started this thread so I feel somewhat obligated to provide some degree of closure to this issue. After considerable diagnostic work & general head scratching the mechanic at the Honda dealership found the problem. I am not a mechanic, but I'll do the best I can to describe what he found. He said after taking the plastic off the right side of the bike he found that the wire that lead to the crankshaft position sensor was routed under the thermostat. The wire had been rubbed to the point where the insulation had been worn thin in places. He put some shrink tube over the worn spots & put it all back together. It seems to run fine now. I don't get that "chugging" at low rpms. I hope this may provide someone else w/some help. As I said I'm not a mechanic, so I'm just repeating what the mechanic told me.

 

[seagrass]

Thanks for the follow up information, what you describe could certainly cause the problem you were experiencing.