Bike stumbling badly on first cold start in the morning, ideas?

[C1xRider]

I've never had that issue with the changing of fuels for the seasons...  I don't think that's it.  It's something that only occurs at a cold start sitting overnight.      Check all the battery connections and check the voltage on the battery before you crank it up.  I'd also check the charging voltage.  Maybe something is amiss there.

The last time I had battery voltage issues (failing battery), I didn't experience anything like this.  I will definitely check the levels though, since a lack of juice to the stick coils (caused by the starter taking everything) could result in a misfire at initial start, that would then allow one or more cylinders to load up, potentially causing what I'm seeing.  At least the theory makes sense in my head.  Good suggestion Jim, thanks!   

It may be too rich.  I see you have a 2010 model.  Try putting it in ECO mode when you start up.  I know mine has the same cold studder but switching to ECO mode helps.

I would have thought there was only one map setting for cold start, independent of having ECO mode enabled or not.  However, I've never tried setting it to ECO mode before starting the bike, so this is an interesting suggestion.  If nothing else (and it actually does reduce fuel at start), it may provide a clue to whether the problem is too lean or too rich (or neither).

Isn't there a way to re-flash the ECU? Or maybe have the dealer do it and see if that doesn't help.

Are we still talking about my C14?  If so, I don't understand this suggestion.  Something has recently changed, causing the problem described above, which to me indicates a malfunction or early signs of a failure.  What would reflashing the ECU have to do with diagnosing this problem?   

[pistole]

- basic things first :

- was anything done to the bike prior to this "problem".

- does your battery start your bike with the same enthusiasm as before.

- have you run a tank of good fuel through her yet.

- does your bike do the cold-start-routine (heightened rpms as the bike warms up and then rpms dropping noticeably after warm up) ?

.

[Son of Pappy]

I wonder if the idle kickup on the throttle bodies is sticking?  Kinda like a stuck open choke.  I'd spray some WD on the left side of the TBs in the area of the throttle spring while rotating the throttle.

[PH14]

You say the bike is stumbling badly in the morning... was it out drinking the night before? 

[connie1]

My guess would be over fueling from a leaky injector or two.  That might explain why it dies when you try to open the throttle.
The rest of the day it doesn't have time to drip fuel into the cylinders to cause an over rich condition.  If you have an infrared thermometer you could check the temps on the header to see if one or more heats up slower than the rest.
We used to do this with older diesel tractors... just feel the manifold after starting to see which injectors were poor.

The reason I first started thinking over fueling is my John Deere diesel in my combine was programmed to dump in lots of fuel on startup and on a cold morning it will cough, sputter and slobber while puking tons of white smoke for the first 20 seconds while hardly able to produce enough power to keep turning running.   Warm starts are a breeze.

Anxious to find out what is actually bothering your bike.

[C1xRider]

- basic things first :
- was anything done to the bike prior to this "problem".

No, nothing.  This came on out of the blue...

- does your battery start your bike with the same enthusiasm as before.

Seems to crank plenty fast, nothing that I deemed suspicious.  It has a very good battery, so I'm not suspecting that to be the problem.

- have you run a tank of good fuel through her yet.

I only run "good" fuel, and this problem has spanned 2 tanks from different stations.

- does your bike do the cold-start-routine (heightened rpms as the bike warms up and then rpms dropping noticeably after warm up) ?

I covered this above already, but to clarify, it always did the cold-start-routine as you mentioned, prior to this issue.  Now it's having trouble just running, until it stabilizes.  After that, it's back to normal, and seems fine.

[C1xRider]

I wonder if the idle kickup on the throttle bodies is sticking?  Kinda like a stuck open choke.  I'd spray some WD on the left side of the TBs in the area of the throttle spring while rotating the throttle.

If that were the case, I would think me cracking the throttle just a little bit would let it clean up and bring the idle up, but that didn't happen.  One time I did try to crack the throttle (gently, as the previous time it killed the engine), and it began to die.  I backed off, and it returned to the stammering / gurgling for another 10 to 15 seconds, then slowly cleaned up and ran normally.

You say the bike is stumbling badly in the morning... was it out drinking the night before? 

If it did, it went without it's FOB.   

[C1xRider]

My guess would be over fueling from a leaky injector or two.  That might explain why it dies when you try to open the throttle.
The rest of the day it doesn't have time to drip fuel into the cylinders to cause an over rich condition.  If you have an infrared thermometer you could check the temps on the header to see if one or more heats up slower than the rest.
We used to do this with older diesel tractors... just feel the manifold after starting to see which injectors were poor.

The reason I first started thinking over fueling is my John Deere diesel in my combine was programmed to dump in lots of fuel on startup and on a cold morning it will cough, sputter and slobber while puking tons of white smoke for the first 20 seconds while hardly able to produce enough power to keep turning running.   Warm starts are a breeze.

Anxious to find out what is actually bothering your bike.

The leaky fuel injector was (and still is) my primary suspicion.  As an experiment, I didn't start the bike yesterday, letting it sit for about 36 hours.  I just went out this morning and did the following :

Put bike on center stand (since I always start it while sitting on the seat with it upright).
Set a drop light near the back, so I could check for exhaust smoke.
Connected my Fluke 87 meter to the power socket that's tied directly to the battery, turned on the ignition, and set it for Min/Max mode
Started the bike, then checked the exhaust.

This time, it only stumbled for a couple seconds, then cleaned up and began ramping up the idle.  The Fluke meter recorded the initial voltage (ignition on) at 12.70VDC, the Min (while cranking the starter) at 10.84VDC, and the max (just before I shut it off) at 14.64VDC.

I checked for any smoke from the exhaust, and saw none.  The smell from the right side muffler was that of raw, unburned gas, while the left side was just normal burnt gas smell.  It could be that the left side had already cleared before I got my nose over there, but I didn't think it had enough time.  This is also suspicious.

I'll have to wait until tomorrow morning to try again, since if I shut it off, it restarts and runs just fine (tried this as well).

So, if it is a dribbling injector, it could be that by waiting longer this time, it had enough time for any excess fuel to evaporate.  I'll try again tonight, after about 12 hours, and see what it does.  After that, the next chance will be tomorrow morning.  At least it runs great the rest of the time.   

[chap]

I notice you guys are talking about your bikes going to a high Idle on warmup. My 2010  doesn't noticeably do this. It just runs at about 1200- 1300 right from startup. Is it really supposed to do this, or are your bikes running a little lean when cold. I only have about 15,000 km (9,000 mi). It has done the same since new.

As to the problem with the OP. I would go along with a leaky injector. The bike is rich until it burns through. A leak down test will show this.

[B.D.F.]

Late to this party, sorry. But I just read this whole thread and I agree with the poster that said simple things first. Before we venture into the world of fuel, spark, timing, plugged injectors, etc. etc., I wonder why the bike will not start on a high idle?

First of all, I would verify that the high idle function is working. When you turn the ignition on the secondary throttle plates fully open, then close, then go to the position needed to affect the high idle for starting (depending on the temperature). The way that works is that on the left side of the secondary throttle plate shaft is the drive plate with a cam that opens the main throttle plates. A really clever and effective design. To check for this, you can start by putting your head down near where the throttle bodies are, on the left side of the bike, and turn the ignition on. You should hear the stepper motor working to go through the entire cycle.

There is an adjustment which consists of a screw and a locknut on the secondary throttle operation plate. It is possible that that has broken off or bent slightly and not engaging the main throttle operating plate. You can easily see and verify the operation of all the parts I am talking about on the left side of the throttle body assembly with the left fairing off the bike. You can watch it cycle and see the main throttles being cammed open. The adjustment itself is covered with yellow paint and there is a warning in the manual that this is not an adjustment (but it is) and nothing can be adjusted (but it can) regarding this function.

So check that first.

The next thing would be that the bike is not setting the engine up for high idle because it does not 'know' what the temperature is. Perhaps a bad temp. sensor? Finding that would be a matter of getting to it, disconnecting it and checking it with a meter. You might use a mild heat source such as a hair dryer to check that the sensor actually changes resistance when its temperature changes. But again, that is all after making sure the mechanical portion of the high idle is working correctly.

Brian

[B.D.F.]

Entirely possible but I think you are looking far, far too deep into this situation. I suspect either a mechanical problem with high idle or a bad temperature sensor. Please see my other post where I detail this.

Even if you have a leaking injector it should not cause the bike to run badly for more than a second or so. Only a tiny amount of fuel can leak out of a leaking injector anyway, and most of that runs past the piston rings and ends up in the crankcase. It is not at all likely that there is really fuel puddling up on top of a piston.

Brian

The leaky fuel injector was (and still is) my primary suspicion.  As an experiment, I didn't start the bike yesterday, letting it sit for about 36 hours.  I just went out this morning and did the following :

Put bike on center stand (since I always start it while sitting on the seat with it upright).
Set a drop light near the back, so I could check for exhaust smoke.
Connected my Fluke 87 meter to the power socket that's tied directly to the battery, turned on the ignition, and set it for Min/Max mode
Started the bike, then checked the exhaust.

This time, it only stumbled for a couple seconds, then cleaned up and began ramping up the idle.  The Fluke meter recorded the initial voltage (ignition on) at 12.70VDC, the Min (while cranking the starter) at 10.84VDC, and the max (just before I shut it off) at 14.64VDC.

I checked for any smoke from the exhaust, and saw none.  The smell from the right side muffler was that of raw, unburned gas, while the left side was just normal burnt gas smell.  It could be that the left side had already cleared before I got my nose over there, but I didn't think it had enough time.  This is also suspicious.

I'll have to wait until tomorrow morning to try again, since if I shut it off, it restarts and runs just fine (tried this as well).

So, if it is a dribbling injector, it could be that by waiting longer this time, it had enough time for any excess fuel to evaporate.  I'll try again tonight, after about 12 hours, and see what it does.  After that, the next chance will be tomorrow morning.  At least it runs great the rest of the time.   

[PH14]

If it did, it went without it's FOB.   

 

[C1xRider]

Entirely possible but I think you are looking far, far too deep into this situation. I suspect either a mechanical problem with high idle or a bad temperature sensor. Please see my other post where I detail this.

Even if you have a leaking injector it should not cause the bike to run badly for more than a second or so. Only a tiny amount of fuel can leak out of a leaking injector anyway, and most of that runs past the piston rings and ends up in the crankcase. It is not at all likely that there is really fuel puddling up on top of a piston.

Brian

I still have trouble believing that lack of, or failure of the fast idle control could be the cause, for the same reasons I gave Chet above.  It just doesn't seem to me that the fuel mixture would be so excessively rich that if the idle was a few hundred RPM low at first start, my attempt to manually open the throttle would result in killing the engine.  I'm not ruling it out, but it seems that gradually opening the throttle like I did, attempting to increase the idle speed, should have cleared it out right away (which it didn't).  A failing sensor could result in excess fuel (mis-information to the ECU), so that's a good suggestion too.

Your comment about the gas just running past the rings is also a good point.  If it were a leaking injector and it leaks past the rings, it seems like there should be some hint of raw gas in the oil.  However, I sniffed the oil at the filler cap, and didn't smell any gas, just the usual combustion by products that oil with some miles on it smells like.  Then again, it started just fine this time too, so ...

Another question :
Does anyone know if the injector rail remains pressurized after the bike is shut off?  In many EFI cars, the pressure is maintained in the system after it's powered off (even for days), and there are lots of warnings about removing that pressure before attempting to work on the system.  I found no such warnings in the Kawi FSM, so perhaps the fuel pump bleeds off the pressure back into the tank?  If so, then there would be no static pressure in the fuel rail, which I would expect would be needed to force a injector to leak when powered off.

I let the bike sit all day today, and just started it again a few minutes ago.  It started clean with no stumbling, and cracking the throttle resulted in instant response (like normal).  The initial idle after it started was about 1400, then it increased to around 1700 as it warmed up, then dropped back to 1200 (normal).  I'll try again in the morning, but maybe it needs to be ridden, then parked overnight.

On a side note, has anyone noticed how much noise comes from the intake ports up front under the headlights?  I was listening to mine while waiting for the idle to come down, and wow, it was loud and fairly high pitched.  This is with the bike in the garage with the doors closed, and with the Two Bros dual exhaust (which is loud by itself).

[B.D.F.]

I believe the fuel system stays pressurized. That does not really matter either though because hydraulics change very, very little when pressurized so again, there just isn't much fuel that would be released if the system de-pressurized (as if through a fuel injector or anywhere else).

What are the overnight temperatures like when the bike starts badly? How about when it starts and runs normally? We are having extremely variable temperatures here in the northeast so if that is the case where you are, it could be what is starting the whole 'poor running' situation.

Does the high idle ever work on your bike?

I still believe there is some simple, direct cause of your problem rather than a complicated, involved cause. Further, things like faulty injectors or coils <usually> do not come and go- they just fail (although it is certainly possible to have a weak coil). The other thing that makes me thing that this is something simple and direct is that the bike runs correctly  in all circumstances other than the very first few moments of a cold start, and not always even then. Weak spark components and erratic fuel delivery usually show up under high engine loads or high engine loads at high RPM.

Again, I would find out why the high idle mechanism is not working. Be the cause a direct mechanical fault or the ECU being misled by a faulty temperature sensor would handily explain your current problem.

Brian

I still have trouble believing that lack of, or failure of the fast idle control could be the cause, for the same reasons I gave Chet above.  It just doesn't seem to me that the fuel mixture would be so excessively rich that if the idle was a few hundred RPM low at first start, my attempt to manually open the throttle would result in killing the engine.  I'm not ruling it out, but it seems that gradually opening the throttle like I did, attempting to increase the idle speed, should have cleared it out right away (which it didn't).  A failing sensor could result in excess fuel (mis-information to the ECU), so that's a good suggestion too.

Your comment about the gas just running past the rings is also a good point.  If it were a leaking injector and it leaks past the rings, it seems like there should be some hint of raw gas in the oil.  However, I sniffed the oil at the filler cap, and didn't smell any gas, just the usual combustion by products that oil with some miles on it smells like.  Then again, it started just fine this time too, so ...

Another question :
Does anyone know if the injector rail remains pressurized after the bike is shut off?  In many EFI cars, the pressure is maintained in the system after it's powered off (even for days), and there are lots of warnings about removing that pressure before attempting to work on the system.  I found no such warnings in the Kawi FSM, so perhaps the fuel pump bleeds off the pressure back into the tank?  If so, then there would be no static pressure in the fuel rail, which I would expect would be needed to force a injector to leak when powered off.

I let the bike sit all day today, and just started it again a few minutes ago.  It started clean with no stumbling, and cracking the throttle resulted in instant response (like normal).  The initial idle after it started was about 1400, then it increased to around 1700 as it warmed up, then dropped back to 1200 (normal).  I'll try again in the morning, but maybe it needs to be ridden, then parked overnight.

On a side note, has anyone noticed how much noise comes from the intake ports up front under the headlights?  I was listening to mine while waiting for the idle to come down, and wow, it was loud and fairly high pitched.  This is with the bike in the garage with the doors closed, and with the Two Bros dual exhaust (which is loud by itself).

[C1xRider]

I believe the fuel system stays pressurized. That does not really matter either though because hydraulics change very, very little when pressurized so again, there just isn't much fuel that would be released if the system de-pressurized (as if through a fuel injector or anywhere else).

What are the overnight temperatures like when the bike starts badly? How about when it starts and runs normally? We are having extremely variable temperatures here in the northeast so if that is the case where you are, it could be what is starting the whole 'poor running' situation.

Does the high idle ever work on your bike?

I still believe there is some simple, direct cause of your problem rather than a complicated, involved cause. Further, things like faulty injectors or coils <usually> do not come and go- they just fail (although it is certainly possible to have a weak coil). The other thing that makes me thing that this is something simple and direct is that the bike runs correctly  in all circumstances other than the very first few moments of a cold start, and not always even then. Weak spark components and erratic fuel delivery usually show up under high engine loads or high engine loads at high RPM.

Again, I would find out why the high idle mechanism is not working. Be the cause a direct mechanical fault or the ECU being misled by a faulty temperature sensor would handily explain your current problem.

Brian

If the system stays pressurized, and there is a injector that is dribbling out fuel, it would leak more fuel if the system was under pressure then if there were no pressure, that's just basic physics.  Without pressure, the only  force would be gravity, and I doubt it would leak much in that case.  Still, given the hazardous nature of working on pressurized EFI systems, I would expect an abundance of warnings in the FSM if it were pressurized (to avoid lawsuits).  If there are any, I didn't see them, and I was specifically looking for them.

The bike is parked in a insulated garage, so the overnight temps seldom get below 50F, and haven't for several months.

When I started it last night, the high idle worked fine (see my post above, 4th paragraph, for details).

I totally agree with looking for the simplest solution, but I also look for the solution that fits within a given theory supported by the observed facts or data points.  So, do you really believe that if the high idle was not working, the amount of fuel from the ECU would be so much that the bike would flood to the point that opening the throttle slightly would kill the engine?  I have trouble buying into that premise, since I've been around engines all my life, and usually when you have a mildly rich condition, adding extra air to the mix has an immediate positive affect.  Not saying it can't happen, just that it seems unlikely in this case.  I would think the amount of extra fuel would have to be significant.
 
I also agree with your comment about the coils and injectors typically failing under load.  That is almost always the case with anything electrical or mechanical, and how I usually find out a component is failing.

There's also another remote possibility that the little rodent that moved in there 2 years ago, munched on another wire that I missed (although I was very thorough in my inspection of all the wires and hoses after that).  Perhaps there's a sensor wire that has damage to the insulation, and with a little corrosion, it's increasing the resistance that's reported to the ECU?  Not sure why that would come and go though, or not affect the bike under all running conditions.

To be fair, the last two times did not reproduced the exact conditions where I observed the problem (by just starting the bike, running it for a few minutes, then shutting it off).  The real test is to ride it for at least an hour. park it overnight, then restart it.  I'm riding it today, so starting it tomorrow morning will be a good test case.

[B.D.F.]

Hydraulics 101: the volume of a hydraulic system (brakes, fuel injection, clutch, everything else on the planet that works using hydraulics) does not change with pressure. Usually stated as 'fluids are incompressible' (they are compressible but for our discusion and virtually all instances in real life, fluids are incompressible). What that means is that if you have a sealed system full on fluid (no air- that would be a pneumatic system even if it was only 1% air and 99% fluid), you can't put any more fluid in the system even if you squeeze on it. The counter to that is that if you come upon a static hydraulic system that has any amount of pressure in it and suddenly release that pressure..... nothing will happen and no fluid will escape. Sounds incredible I know but it is true. Without a fuel pump behind it to make it a dynamic system, venting the pressure on a F.I. system will not release any fluid really. Now there is a very small rub here: when the system is pressurized, some parts of the system are elastic and therefore stretched; the fuel injector hoses are just a tad bigger when pressurized. When the system is tapped, the hoses push a small amount of fluid out due to the hose's contraction but it won't amount to much at all. In the end, a leaking fuel injector on a static system (no fuel pump running) simply cannot leak enough fuel into a cylinder to worry about.

Even a leaking fuel injector in operation leaks precious little fuel actually. The leak- down test is something like 10 seconds but the fuel injector will actually cycle many times per second on a running engine, even at idle.

Per your stated observations, yes, I believe the high idle was not working, at least intermittantly, on your bike. You said so. It does not matter why it was not working, just that that was the case. Would I believe a loose high- idle adjuster screw could rattle into and out- of a position so that it worked sometimes? Yes, I do. In fact I think that is more likely and much better fits the facts as I am aware of them (both regarding your bike and the physical word at large) than I would think you have an injector, on a static fuel system, that is leaking enough fuel into a cylinder, and that fuel is sitting there <not> dribbling down past the rings on the piston, sufficiently that there would be a build- up of fuel in that cylinder to cause very poor running for several seconds after start-up. Logic points me to something else, something far less complicated. You could have a set of spinning rings in one cylinder (it happens- the cylinder wall wear pattern causes a ring(s) to turn while inside a running engine) and every now and then the ring gaps align, causing a loss of compression leading to rough running, misfiring, fuel in the exhaust, etc., etc. The logic fits but it is unlikely that that is your problem so I discount it in favor of something more likely.

In fact, now that you mention the rodent having spent a little time visiting your bike, that is the theory I like best so far. The little fellow chewed <mostly> through something and that something is now making intermittent contact. Much more likely in my opinion than fretting wear on the injector's internal surface, caused by an amorphous grind left by a worn and clogged CBN grinding wheel used to finish the pin, is now allowing fuel to puddle in the engine. :-)  Both are possible but only one is likely IMO.

Again my advise remains: check the high idle mechanics on the left side of the throttle body assembly and added to that, take a strong flashlight and glasses if your vision is better that way, and poke around carefully to see if there is any wiring damage done by the cute little furry fellow who left those 'specks of pepper' behind him.... 

Brian

If the system stays pressurized, and there is a injector that is dribbling out fuel, it would leak more fuel if the system was under pressure then if there were no pressure, that's just basic physics.  Without pressure, the only  force would be gravity, and I doubt it would leak much in that case.  Still, given the hazardous nature of working on pressurized EFI systems, I would expect an abundance of warnings in the FSM if it were pressurized (to avoid lawsuits).  If there are any, I didn't see them, and I was specifically looking for them.

The bike is parked in a insulated garage, so the overnight temps seldom get below 50F, and haven't for several months.

When I started it last night, the high idle worked fine (see my post above, 4th paragraph, for details).

I totally agree with looking for the simplest solution, but I also look for the solution that fits within a given theory supported by the observed facts or data points.  So, do you really believe that if the high idle was not working, the amount of fuel from the ECU would be so much that the bike would flood to the point that opening the throttle slightly would kill the engine?  I have trouble buying into that premise, since I've been around engines all my life, and usually when you have a mildly rich condition, adding extra air to the mix has an immediate positive affect.  Not saying it can't happen, just that it seems unlikely in this case.  I would think the amount of extra fuel would have to be significant.
 
I also agree with your comment about the coils and injectors typically failing under load.  That is almost always the case with anything electrical or mechanical, and how I usually find out a component is failing.

There's also another remote possibility that the little rodent that moved in there 2 years ago, munched on another wire that I missed (although I was very thorough in my inspection of all the wires and hoses after that).  Perhaps there's a sensor wire that has damage to the insulation, and with a little corrosion, it's increasing the resistance that's reported to the ECU?  Not sure why that would come and go though, or not affect the bike under all running conditions.

To be fair, the last two times did not reproduced the exact conditions where I observed the problem (by just starting the bike, running it for a few minutes, then shutting it off).  The real test is to ride it for at least an hour. park it overnight, then restart it.  I'm riding it today, so starting it tomorrow morning will be a good test case.

[C1xRider]

Hydraulics 101: the volume of a hydraulic system (brakes, fuel injection, clutch, everything else on the planet that works using hydraulics) does not change with pressure. Usually stated as 'fluids are incompressible' (they are compressible but for our discusion and virtually all instances in real life, fluids are incompressible). What that means is that if you have a sealed system full on fluid (no air- that would be a pneumatic system even if it was only 1% air and 99% fluid), you can't put any more fluid in the system even if you squeeze on it. The counter to that is that if you come upon a static hydraulic system that has any amount of pressure in it and suddenly release that pressure..... nothing will happen and no fluid will escape. Sounds incredible I know but it is true. Without a fuel pump behind it to make it a dynamic system, venting the pressure on a F.I. system will not release any fluid really. Now there is a very small rub here: when the system is pressurized, some parts of the system are elastic and therefore stretched; the fuel injector hoses are just a tad bigger when pressurized. When the system is tapped, the hoses push a small amount of fluid out due to the hose's contraction but it won't amount to much at all. In the end, a leaking fuel injector on a static system (no fuel pump running) simply cannot leak enough fuel into a cylinder to worry about.

Even a leaking fuel injector in operation leaks precious little fuel actually. The leak- down test is something like 10 seconds but the fuel injector will actually cycle many times per second on a running engine, even at idle.

Per your stated observations, yes, I believe the high idle was not working, at least intermittantly, on your bike. You said so. It does not matter why it was not working, just that that was the case. Would I believe a loose high- idle adjuster screw could rattle into and out- of a position so that it worked sometimes? Yes, I do. In fact I think that is more likely and much better fits the facts as I am aware of them (both regarding your bike and the physical word at large) than I would think you have an injector, on a static fuel system, that is leaking enough fuel into a cylinder, and that fuel is sitting there <not> dribbling down past the rings on the piston, sufficiently that there would be a build- up of fuel in that cylinder to cause very poor running for several seconds after start-up. Logic points me to something else, something far less complicated. You could have a set of spinning rings in one cylinder (it happens- the cylinder wall wear pattern causes a ring(s) to turn while inside a running engine) and every now and then the ring gaps align, causing a loss of compression leading to rough running, misfiring, fuel in the exhaust, etc., etc. The logic fits but it is unlikely that that is your problem so I discount it in favor of something more likely.

In fact, now that you mention the rodent having spent a little time visiting your bike, that is the theory I like best so far. The little fellow chewed <mostly> through something and that something is now making intermittent contact. Much more likely in my opinion than fretting wear on the injector's internal surface, caused by an amorphous grind left by a worn and clogged CBN grinding wheel used to finish the pin, is now allowing fuel to puddle in the engine. :-)  Both are possible but only one is likely IMO.

Again my advise remains: check the high idle mechanics on the left side of the throttle body assembly and added to that, take a strong flashlight and glasses if your vision is better that way, and poke around carefully to see if there is any wiring damage done by the cute little furry fellow who left those 'specks of pepper' behind him.... 

Brian

I'm well aware that fluids don't compress, and steel lines don't expand, but there are other factors at work.  Any rubber lines can expand, providing a potential energy source to push out fuel if there's some place for it to go.  Also depending on the construction of the pump, it may have a mechanism that is left in a state after power is cut, prepared to push more fuel if the existing pressure drops. 

I have removed fuel lines from EFI equipped vehicles, and observed fuel spraying out (5 to 10 feet from the source), with quite a lot of fuel coming out.   Perhaps this isn't the case with the C14, but don't believe for a moment it can't happen.  Also, injectors can fail.  If the fuel system has any stored (potential) energy to push fuel, and a injector isn't sealing properly, it will leak (probably slowly).

I'm not sure why you stated I said my fast idle was not working, because I never said that.  I have zero tolerance for that, so please don't do it.  I have never observed the fast idle behaviour on any other C14, but the way I describe mine working earlier is how it has always worked since it was new.

I started the bike this morning, and it started up fine.  About 10 seconds after it lit off, it stumbled or misfired, then continued warming up normally.  Since I can't get to the throttle bodies without taking the plastics off, I may not be able to peek in there for awhile (kind of a PITA with the tip over bars installed).  I did discover I have another slight antifreeze leak, so I'll be chatting with the dealer about it.  That may result in a opportunity to look in there soon.

The critter that built the nest in there 2 years ago didn't do much damage.  I was very careful to inspect all wires and hoses thoroughly.  Most of the harness in there is wrapped with tape, so it's pretty obvious if it's damaged.  The few wires I found that were gnawed on, only had a little bit of insulation missing.  Now that doesn't mean one of it's relatives (or the same one, since I don't know if I caught the original one) may have moved back in there after I removed the nest.

BTW, all the pistons I've ever used have lock pins in the ring grooves to prevent the rings from rotating.  Are you stating the C14 pistons do not?

[lather]

I don't have any ideas but maybe can provide some info about fuel injector leaks.
I recently had the fuel injectors on my 99 Honda VFR tested and cleaned by RC Engineering in California. (Russ Collins of dragbike fame for us old guys) This seems to have solved the problem I was having with fuel accumulating in my crankcase apparently due to a "dripping" injector.  At no time did my VFR ever exhibit hard starting or bad running in the past three or four years prior to this problem. The only way I was alerted to it is that I happened to check the oil level sight glass and saw that it was over the top. I say "happened" because I had gotten into the habit of almost never checking between 6000 mile oil change intervals because for the 12 years and 120,000 miles I have owned the VFR  the oil level had never moved between changes until this time. The VFR forum I'm on guided me to check for a leaking fuel pressure regulator and leaking injectors.These tests were negative. The leaking injector test was performed by priming the pump multiple time then probing the injector orifice with a rolled up paper towel. The VFR gurus say the the pressure normally bleeds off within about 15 minutes after shut down.

With no other ideas I pulled the injectors and sent them to RC, cost was about $24 each plus $15 shipping. They mount the injectors in a test rig and observe the spray pattern, and measure the flow rate, clean then retest. My #3 injector spray pattern was described as "dripping". The others were either "fair" or "good". The flow rate for #3 was actually lower than the others at 220 cc/min vs an average of 242 for the other three. After cleaning the flow rates were 249-251 and all for spray patterns were described as excellent.

The test and report seem to me to be more oriented toward racing/high performance applications as opposed to maintenance or diagnostic purposes so much of the info provided was not of much value to me. However my conclusion was that the report suggests that the dripping injector was the probable cause of fuel accumulation in m the oil. I have only put about 700 miles on the VFR since re-installing the cleaned injectors but so far the oil level has remained static.

One thing that I found interesting was that despite the reported 'BAD" injector,  the VFR alway started easily on  the first try (with manual "choke") and quickly warmed up to normal running within 15 seconds and never exhibited any sign of poor performance.

 

[C1xRider]

I don't have any ideas but maybe can provide some info about fuel injector leaks.
I recently had the fuel injectors on my 99 Honda VFR tested and cleaned by RC Engineering in California. (Russ Collins of dragbike fame for us old guys) This seems to have solved the problem I was having with fuel accumulating in my crankcase apparently due to a "dripping" injector.  At no time did my VFR ever exhibit hard starting or bad running in the past three or four years prior to this problem. The only way I was alerted to it is that I happened to check the oil level sight glass and saw that it was over the top. I say "happened" because I had gotten into the habit of almost never checking between 6000 mile oil change intervals because for the 12 years and 120,000 miles I have owned the VFR  the oil level had never moved between changes until this time. The VFR forum I'm on guided me to check for a leaking fuel pressure regulator and leaking injectors.These tests were negative. The leaking injector test was performed by priming the pump multiple time then probing the injector orifice with a rolled up paper towel. The VFR gurus say the the pressure normally bleeds off within about 15 minutes after shut down.

With no other ideas I pulled the injectors and sent them to RC, cost was about $24 each plus $15 shipping. They mount the injectors in a test rig and observe the spray pattern, and measure the flow rate, clean then retest. My #3 injector spray pattern was described as "dripping". The others were either "fair" or "good". The flow rate for #3 was actually lower than the others at 220 cc/min vs an average of 242 for the other three. After cleaning the flow rates were 249-251 and all for spray patterns were described as excellent.

The test and report seem to me to be more oriented toward racing/high performance applications as opposed to maintenance or diagnostic purposes so much of the info provided was not of much value to me. However my conclusion was that the report suggests that the dripping injector was the probable cause of fuel accumulation in m the oil. I have only put about 700 miles on the VFR since re-installing the cleaned injectors but so far the oil level has remained static.

One thing that I found interesting was that despite the reported 'BAD" injector,  the VFR alway started easily on  the first try (with manual "choke") and quickly warmed up to normal running within 15 seconds and never exhibited any sign of poor performance.

That is very interesting, and good information, thanks for posting it.   

Time will have to tell what's happening with mine, since the problem seems to have taken a hiatus.

[B.D.F.]

Specifically addressing the part of your post I highlighted, you implied that your fast idle was not working by saying the following, and I quote:

"It's always started clean cold, and ran great since new, before this.  Usually, it would start and go immediately to fast idle speed, and the throttle was very responsive if I touched it."

The meaning I took from those two sentences was that the fast idle was either not currently working or only working intermittently and coupled with your current poor running characteristics upon start-up. If that is not the case, I suggest you try and be more clear in the future posts because that is still the meaning I take from your statement.

As far as your implied threat in this last post, not sure what I am to stop doing but I believe I will continue to behave exactly as I have in the past; it has served me reasonably well so far and I believe it is perfectly acceptable behavior, just as I expect and appreciate from others. But as we live on different coasts of the US, and I am a free person in good standing as a citizen of this country, it does amuse me that you have issued me any type of command without the slightest hope of enforcement. You would have equal luck squelching gravity in my opinion but by all means, give it a shot (either one). :-)

As to the there being pins to orientate and time piston rings, to the best of my knowledge they are only used in engines with ports; specifically two- cycle engines. No four cycle engine I have ever seen uses piston ring pins to align them as they make the rings and pistons far more expensive to produce and make the sealing of the ring gap much less effective. In fact, many modern piston rings are more complex than simple square ends to increase their ability to resist leaking. What is inside the C-14 regarding piston ring pins I do not know but expect they are not pinned. In any event, a split metal piston ring in a metal piston is not a 100% seal as a rubber O-ring would be and all of them leak to varying extents. All piston rings allow liquids and gasses to pass by (called blow-by when the engine is running, and simply leak- down when the engine is not running). Carbureted  engines can occasionally leak enough to cause a hydraulic lock on a cylinder but fuel injected engines just do not have the potential volume of fuel available to cause this. On carbureted  engines a cylinder full of fuel only happens when float valve in the carburetor fails and essentially the entire fuel tank is allowed to drain into one cylinder. It is also highly unlikely that a leaking fuel injector is causing intermittant poor running because they just do not leak enough for that usually, unless a piece of debris is caught inside the injector and then they leak so much fuel that the engine simply cannot be made to run right other than a wide open throttle (and not usually then either) because they pump so much excess fuel into a cylinder.

All the way back to the point, I do not believe it is a reasonable, logical place to start looking for the cause of a intermittently lousy running engine on start- up by checking the fuel injectors. There are other causes that are far more likely to exist IMO and experience.

I remain willing to help if I can but will need more information on which to base better opinions.

Brian

I'm well aware that fluids don't compress, and steel lines don't expand, but there are other factors at work.  Any rubber lines can expand, providing a potential energy source to push out fuel if there's some place for it to go.  Also depending on the construction of the pump, it may have a mechanism that is left in a state after power is cut, prepared to push more fuel if the existing pressure drops. 

I have removed fuel lines from EFI equipped vehicles, and observed fuel spraying out (5 to 10 feet from the source), with quite a lot of fuel coming out.   Perhaps this isn't the case with the C14, but don't believe for a moment it can't happen.  Also, injectors can fail.  If the fuel system has any stored (potential) energy to push fuel, and a injector isn't sealing properly, it will leak (probably slowly).

I'm not sure why you stated I said my fast idle was not working, because I never said that.  I have zero tolerance for that, so please don't do it.  I have never observed the fast idle behaviour on any other C14, but the way I describe mine working earlier is how it has always worked since it was new.

I started the bike this morning, and it started up fine.  About 10 seconds after it lit off, it stumbled or misfired, then continued warming up normally.  Since I can't get to the throttle bodies without taking the plastics off, I may not be able to peek in there for awhile (kind of a PITA with the tip over bars installed).  I did discover I have another slight antifreeze leak, so I'll be chatting with the dealer about it.  That may result in a opportunity to look in there soon.

The critter that built the nest in there 2 years ago didn't do much damage.  I was very careful to inspect all wires and hoses thoroughly.  Most of the harness in there is wrapped with tape, so it's pretty obvious if it's damaged.  The few wires I found that were gnawed on, only had a little bit of insulation missing.  Now that doesn't mean one of it's relatives (or the same one, since I don't know if I caught the original one) may have moved back in there after I removed the nest.

BTW, all the pistons I've ever used have lock pins in the ring grooves to prevent the rings from rotating.  Are you stating the C14 pistons do not?