My dealer has no idea, and they're very good - VIDEOS ADDED!

[Kingbee]

Problem: When my engine reaches full operating temperature, and my volt meter is below 12V (fan, driving lights & brake on) it starts missing and idling irratically, RPMs dropping to 500 or lower, and immediately back to 900 or so. There is no rhythm to this erratic miss/ idle behavior. It will not happen when engine is cold, no matter how low the voltage is, or how low the RPMs are. The minute I raise the RPMs (12 - 1,500) when the engine is hot, voltage increases and it smoothes right out.
This is very disconcerting in traffic at lights as it always seems like it's going to die.
I need to get to the bottom of this, as Inzane is a 3K ride for us, and I don't want to risk it getting worse, and stranding us.

I have:

Replaced the coils & wires
Replaced the ICM
Replaced the ignition pulse generators
Replaced the plugs
Tried disconnecting the ECT sensor
Serviced the starter relay & associated wiring
Disconnected the alternator (dealer suggested that to see if mis-fire would then occur at higher RPMs)
Serviced the fuseable link
Cleaned the carbs, installed 38 jets and installed all Interstate internals

NONE of the above has had any effect on this naughty behavior

The only other thing I have't tried yet is disconnecting the Audiovox cruise, as it does connect to the brake light circuit, and applying the brakes aggravates this condition, as stated above.

[Thunderbolt]

with all those bikes, I know you must have one.  Or swap batteries with another bike.

[Scott from FL, now in Maine]

I am definitely no expert, but it sounds to me like a voltage regulator or battery problem. I lean toward the battery. a bad cell in it can cause a draw on the system and at low idle your Altenator can't keep up with that draw. Disconnect the battery and with jumper cables connect it to another battery, even a car battery thats good, but disconnected from the car. Warm up the bike and see if the problem goes away. Just be careful not to short those cables to the frame    I am curious what you find out.

[98valk]

[The only other thing I have't tried yet is disconnecting the Audiovox cruise, as it does connect to the brake light circuit, and applying the brakes aggravates this condition, as stated above.]

sounds like u have your answer, an open circuit/short, bad/corroded ground connection somewhere.  when u increase the rpms the voltage increases overcoming the condition.
most likely a corroded and/or bad connection.

[Kingbee]

But, it only happens when up to operating temp. Before that, everything is perfect.

I forgot in my original post:

New battery (Dealer suggested, but needed anyway)
New high output alternator
Grounds cleaned and checked

I have another ICM coming, Interstate version, but that's just for fun, as I've already replaced the original.

Keep thinking guys!

[Scott from FL, now in Maine]

Only suggestion I have at this time is to disconnect everything you can and run it till get gets hot and see if the voltage still drops to low. This can eliminate things as the problem. If it runs right with all disconnected, start conecting one by one and watch for the trouble to return. You can also do this to a certain extent by pulling all fuses that aren't needed to run. I'll keep thinking about this. it sounds like a tough puzzle. 

[Robert]

A couple of things come to mind I would check to see if the fuel valve is letting the fuel flow at idle. You didn't say if it was only at idle but with the voltage that low it has to be at idle and also I am assuming that anything above that it runs fine. Keep the fuel valve on and physically check to make sure you have good fuel flow and plug the vacuum line and take it for a ride. Valks are a bit unique in that there are wild swings in the vacuum that goes to the fuel valve as seen by your balance gauge and the fact that the oem valve is a pos may pose a problem. And yes only at idle or lower rpms.  If I remember correctly there is a bunch of wires joined together in the harness around the air filter and there is no indication that they are there. Well the splice that holds all them together is corroding and causing all kinds of strange problems like yours. If you go back in the tech articles you may find more info on it. I cannot remember if it was power or ground that was connected but I remember the approximate location and the problems sound like yours. You can test with a volt meter when its doing its thing to see if the voltage is lower at the coils and the ignition module or even the brake circut.

[Dogg]

A couple of things come to mind I would check to see if the fuel valve is letting the fuel flow at idle. You didn't say if it was only at idle but with the voltage that low it has to be at idle and also I am assuming that anything above that it runs fine. Keep the fuel valve on and physically check to make sure you have good fuel flow and plug the vacuum line and take it for a ride. Valks are a bit unique in that there are wild swings in the vacuum that goes to the fuel valve as seen by your balance gauge and the fact that the oem valve is a pos may pose a problem. And yes only at idle or lower rpms.  If I remember correctly there is a bunch of wires joined together in the harness around the air filter and there is no indication that they are there. Well the splice that holds all them together is corroding and causing all kinds of strange problems like yours. If you go back in the tech articles you may find more info on it. I cannot remember if it was power or ground that was connected but I remember the approximate location and the problems sound like yours. You can test with a volt meter when its doing its thing to see if the voltage is lower at the coils and the ignition module or even the brake circut.

it is an ignition break down. you have replaced everything but the wires.check what robert posted. leads to the coils may be the culprit if they are in that cluster he mentioned...

[junior]

well walt, i dont know how to break this to you but you have a sick valk. intead of servieing the starter selinoid..........replace it. i serviced mine last year and the ole girl left me stranded yesterday. ran grat cold, spit and sputtered coughed when hot. i had stopped for coffee went back out to get going, turned the key and no juice!!!!!!!!!!!!!!!! no lights no horn not even a click. took the side cover off checked the fuses, know it wasnt the selinoid cause i had just serviced it last year an it looked good no distortion from a meltdown , so i started to poke and prod the wire harness still had my key on pulled the selinoid from its holdeer and tried to rmove the conector  and dam it was stuckgave it a little twist back and forth tring to remove it and poof had lights , long story short i got it home got it tore down, and the sevice i did to it last year just wasnt enuff i had cleaned it with contact cleaner used dilectic grease, so instead if turning green with corostion it was all brown and nastymelted the 30 amp fuse and conector inturnaly. so now i am waiting on HLD for a new sel,harness to show up.i had fpound the part # in the genaric parts list on the shop talk page. but i would start there walt do a real good insp. if your starter sel.  if it gets hot and makes a poor contact it will make your bike run like crap. just a place to start.

[Tundra]

Kingbee, Please post your culprit when you get it figured out, Curious ???

[R J]

But, it only happens when up to operating temp. Before that, everything is perfect.

I forgot in my original post:

New battery (Dealer suggested, but needed anyway)
New high output alternator
Grounds cleaned and checked

I have another ICM coming, Interstate version, but that's just for fun, as I've already replaced the original.

Keep thinking guys!

Kingbee, just for sheets and grins, find this connector in your great big old rubber boot under the right side cover and have a check look see if it looks like this, if so, here is the part # needed to repair......



Part # follows.



This repair kit is made for a Gold Wing, but it will work in the Valkyrie.    If memory serves me correctly, I had to move 1 wire in the plug to make it match and work..........   Not hard to move the wire, put a small flat blade screw driver in the slot next to the little spring , push and pull on the wire.  It should pop right out.   Just push it in the correct hole and presto, ya is done.   OH, did I say do this before ya get it tied in?     Just compare the wire sizes  and color and go for it......

[junior]

that is one of the parts i just ordered, right along with the selinoid and mine didnt look that good,the 30 amp fuse was welded to that plug

[BOZ]

The high output alternator can cause a "no charge" or "discharge" condition at rpms below 1200. Did you buy it from M.A.R.S.? Ken does excellent alternator re-builds, but he will tell you (as he did me) that the high output alternator he re-builds for the Valkyrie generally needs to be run above 1200 rpms to get a good charge. This is due to the additional weight he adds to the internals of the high output alternator. You might want to call Ken at M.A.R.S. to verify this, if that's where you got your alternator.

I have re-set the idle on my Valk (with the M.A.R.S. high output alternator) to about 1000 rpms and don't have a serious problem with it.

[Airetime]

Problem: When my engine reaches full operating temperature, and my volt meter is below 12V (fan, driving lights & brake on) it starts missing and idling irratically, RPMs dropping to 500 or lower, and immediately back to 900 or so. There is no rhythm to this erratic miss/ idle behavior. It will not happen when engine is cold, no matter how low the voltage is, or how low the RPMs are. The minute I raise the RPMs (12 - 1,500) when the engine is hot, voltage increases and it smoothes right out.
This is very disconcerting in traffic at lights as it always seems like it's going to die.
I need to get to the bottom of this, as Inzane is a 3K ride for us, and I don't want to risk it getting worse, and stranding us.

I have:

Replaced the coils & wires
Replaced the ICM
Replaced the ignition pulse generators
Replaced the plugs
Tried disconnecting the ECT sensor
Serviced the starter relay & associated wiring
Disconnected the alternator (dealer suggested that to see if mis-fire would then occur at higher RPMs)
Serviced the fuseable link
Cleaned the carbs, installed 38 jets and installed all Interstate internals

NONE of the above has had any effect on this naughty behavior

The only other thing I have't tried yet is disconnecting the Audiovox cruise, as it does connect to the brake light circuit, and applying the brakes aggravates this condition, as stated above.

Sounds like you got a relay hot enough for it to be shorting out. I'd inspect all of the relays and look for signs of overheating. It makes sense as the higher level of output overrides the short. Check all connections as well. You might want to check the starter relay as well. or wander around the electricalhttp://www.rattlebars.com/valkfaq/schematics/

[Kingbee]

but nothing changed after installing it, and I have set my idle to 1000 RPM.

Robert, I'm using the electric fuel valve.

[Robert]

You may use the electric fuel valve but do you connect to the tank through the original valve if so then that still may be your problem. Dont forget to check the voltage to the coils and ignition module.

[Kingbee]

I've completely gutted the petcock, except for the ball valve.  I'm not sure where I can check the voltage for the ICM, though.
I re-checked the starter relay connections & fuse & everything is A OK.

Again, this issue only arises when the engine gets up to full operating temp, which is why I tried disconnecting the ECT sensor, to no avail.

Perhaps I'll video the tach tomorrow when it's acting up.

[Challenger]

Hey Kingbee, let me through one at you that I found a buddies bike. Lights would dim and run rough intermittenly. The cooling fan brgs were bad and would draw a lot of amps when it kicked on, (not enough more to blow a fuse) fan would still run but noticably slower, replaced fan and all is well with the world. Just another thought, good luck with your project 

[Novavalker]

Hey Kingbee, let me through one at you that I found a buddies bike. Lights would dim and run rough intermittenly. The cooling fan brgs were bad and would draw a lot of amps when it kicked on, (not enough more to blow a fuse) fan would still run but noticably slower, replaced fan and all is well with the world. Just another thought, good luck with your project 

Try pulling the fuse for the cooling fan, let the bike warm up and see if it still acts up.

I sent you an email Kingbee with the splice repair document. It might be of some help.

[Kingbee]

That's an interesting idea.  However, when I installed the pods on my bike, I installed an Interstate radiator/fan assembly to get the brackets I needed, and there was no difference in this situation, so I doubt if it's the cause.

[Kingbee]

This first video documents how well the bike idles under full electrical load while engine is still cold, even though the voltage is low:

Cold idle	powered by Aeva

This video shows how erratic the idle becomes once the bike is heated up under the same electrical load.  It's not the carbs, as increasing the idle a bit - still on the pilots - smoothes things right out.  I didn't have the patience to let the bike get hotter, but it then gets worse, to the point where it quit once.  And why, when the RPMs drop so low, does it recover?

Erratic warm idle with electrical load	powered by Aeva

More thoughts welcome!

[Bagger John - #3785]

Have you put a voltmeter across the battery and monitored the voltage before and during the misfire event...and afterward, as you give it more gas?

ETA - nevermind...you did. Didn't see the video content 'til now.

[Bob E.]

This is a thought totally from left field...but could your choke/enrichener circuit be sticking open?  This could explain why it runs ok when cold, then stumbles when it gets hot.  Just another wild goose for you to chase.

[NiteRiderF6]

Hey Kingbee... I have been following this thread over the last couple of days and..... It looks like your new high output alternator isn't generating enough current until your RPM's exceed 1100 - 1200 RPM's.... I'm wondering if your new alternator isn't spinning fast enough to put out sufficient current to run your electrics at such a low idle.

I would set the idle RPM's on about 1200 and see what happens when your bike gets hot....

I suspect your alternator is performing poorly at low RPM.... I believe I would ask for replacement as 1200 RPM's is too high to run at idle for our bikes.... Good Luck!

[Kingbee]

I did call the gentlemen at M.A.R.S.  He reiterated, that, for more watts, there was a small decrease in max volts, and that it really doesn't put out much at less than 1000 RPM. He suggested I raise the idle to 1,200, but that seems a little "busy' to me.

[size=12Why does this only happen at operating temp?pt][/size]

[NiteRiderF6]

Weak electrical components (could be one of several) may only exhibit their weakness at elevated temps.... If you have a heat gun (I'm sure you do) you could try heating them up one at a time until you see a change in their output, or change them out one at a time, i.e. coils, relays, etc..... I know you just changed a lot of that out, but you can get "bad" new parts too.

Either way, I think the shortest way to get to the root cause is to change out the alternator, I'd try a Honda alternator, which would eliminate the MARS variable, then proceed with your troubleshooting, if that doesn't change things drastically. I know a couple of guys who own Wings and tried the high output alternator and wound up taking it off because of symptoms like you describe.

When I was watching your videos, the first thing I noticed is that the output from your alternator was low (under 12 Volts) until you revved above about 1200 RPM's.... then it looked to even out and looked more normal for a running bike. Having changed out all of the items that you outlined, makes me suspect the alternator.... I know that we don't like to run our idle speed at 1200, as optimum seems to be about 800 or so... for my bike it does anyway. When I run it much higher, it seems to be harder to shift when stopping, plus it just runs hotter and louder as well.

[Kingbee]

I took out a perfectly good alternator to put the MARS unit in, because of all my lights, heated grips and heated clothing for two people. I didn't want to be in a wattage defecit in cold weather.
This problem pre-existed the alternator replacement.

I'm just going to raise the idle speed bit by bit and see what happens.  I.O.W., I'm throwing in the towel.

[Dogg]

ok, now that i was able to hear it and see tach, it seems to me to be a FUEL problem. colaping line or vent of something. i dont care if all are new, maybe a line is getting smooshed or being sucked flat. irractic idle, without any pop, to me, is a fuel issue. I wish i was there. i couldd tell ya. check complete fuel system, whether is brand new or not. a kink in the line may even cause it. or a petcock vacuum issue, but i believe it IS fuel not wiring.

[Dogg]

as a matter of fact, put it on an IV and see if it doesnt run better. close tank, run a IV hose to the fuel line, making sure there are no bends in teh line. see how it runs. might hafta remove tank to properly do this

[Madmike]

So is this what is happening...??

Engine is cold, ICM advances spark because of ECT and is able to carry the load.  If you go through the posts on the ETC mod there are some remarks that the guys that have done this get a higher engine idle when the advance is left on after the engine warms up.

Engine warms up and the ECT opens and ICM goes back to normal timing and operation, alternator load is such that engine has hard time maintaining RPM, as engine slows down the Alternator eventually cuts out reducing load and so engine accelerates, alternator cuts back in and cycle start again.

[Scott in Ok]

Walt,

I've been following this thread also.

Based on the things you have explained, I can't see it being a fuel issue.  I could blame low vacuum if you had a vacuum petcock but since you don't...that can't be it.  The fact that it runs better at a higher RPM pretty much rules out a vent issue as well. (or fuel in general)

A few comments.  First is the ECT, which is the obvious reason it would idle better when its cold.  If you took this out of the circuit, and it still ran the same, that rules that out. If it was a problem I would expect it to idle roughly without the ECT when the bike is cold.  What if you left the ECT on all the time(ECT mod)?

Second is the low voltage issue.  Low Voltage at idle could cause some weird things under a full load but still does not explain why it runs well cold, and idle rough at operating temperature.  I had my alternator go out on me 1000 miles from home a few years ago.  I unplugged everything and basically ran the bike off the battery(no lights of any kind).  We swapped batteries with another bike every 100 miles or so(or when the battery voltage got down to less than 10v)  The bike ran fine even at 10v.  I did this for 1000 miles.  My point being I don't think the voltage at 12v or 11.7v would cause this.(other than being hard on the battery)

The last thing is a temperature issue, or a combination of temperature/low voltage.  How you trace that down, I have no idea.

Maybe you could put a voltmeter(digital with better resolution) straight to the battery, then increase the idle in very small amounts to see if there is a point where the voltage gets high enough and the problem goes away.  Still does not explain the cold/operating temp difference..but you might learn something from it.

Does this happen when all those accessories are turned off?(normal operating load)

-Scott

[Kingbee]

Mike, I have removed the fusable link from the alternator circuit = no output or load.  The RPMs increased a bit, but still acted the same way (erratic)

Scott, if the driving lights are off, the fan isn't running and the brakes aren't on, the problem goes away.  I've measured the voltage at the battery with a DVM, and that meter in the pod is about as close as it can get to being "right on".


I'm swingin' the towel over my head now, getting ready to let go,,,,

[Madmike]

Walt said "Scott, if the driving lights are off, the fan isn't running and the brakes aren't on, the problem goes away.  I've measured the voltage at the battery with a DVM, and that meter in the pod is about as close as it can get to being "right on"." quote

Walt does the problem occur if the brakes are applied but the driving lights and fan are off?  I saw that you mentioned the brake light earlier and the electrical schematic shows a common ground between the ICM and taillight/brakelight circuit which you may well have already checked as others have mentioned the grounds.  Another possibility (going way out on the limb now scratchin' and clawin') is corrosion in the taillight socket.

[Scott in Ok]

Scott, if the driving lights are off, the fan isn't running and the brakes aren't on, the problem goes away. 

Well heck, just unplug the fan, driving lights and don't use the brakes! LOL 

What if you hooked up an external battery charger, at 10 amps or so while its doing that crazy stuff.....would the problem still exist?

-Scott

[semo97]

Just a thought did you get the audiovox wire conected to the correct side of the coil?

[Robert]

Man Walt you are really getting the hang of this video thing nice touch and it really helps to hear the thing running. I took a look at the video and had a couple more ideas. It really sounds as if one coil or cylinder is cutting out. I agree with Scott's suggestion to put a battery charger on it while its doing its thing. Hook up a 10 amp charger or jump cables to another battery while the bike is running and missing and see if it smooths out. Its not for the purpose of checking that the voltage that the gauge shows is accurate but the if the voltage goes to low is that the problem. Technically 12v should be ok but if you bring the voltage up to 14 and the problem goes away then you have made a diagnosis that its voltage related. If it does then you know its electrical if not then fuel. I was wondering if the voltage had anything to do at all with the running problem or you are just confusing the real issue. This really needs to be done to hopefully narrow down the possibilities. When you did the valve you really should take out the ball it doesn't need it and the seal is around the shaft for the handle so don't worry about taking it out and not sealing.

[Kingbee]

I haven't had enough time to troubleshoot today, but I did manage to put the Interstate ICM in, and no change.

On your petcock comment, if I remove the ball, there won't be any reserve.......

[Robert]

Put the ball back in once you have your problem fixed just a temporary measure. Also did you check the diaphragms when you did your change over to 38 slow jets?

[Scott in Ok]

I would consider putting the smooth idle when cold out of your mind for the sake of resolving the problem.  Instead of focusing on why it idles good cold, and bad when warm, I would focus on finding why it idles bad when warmed up.  That simplifies the troubleshooting....

I still think hooking up a battery charger to bring the voltage up at idle would be my next step.  It should eliminate the voltage issue one way or the other.

Good luck Walt, with whatever you choose to do.

-Scott

[Kingbee]

Actually, it's synched great, per this video. This instrument greatly exaggerates the synch differences due to it's sensitivity, although a little slow to respond.
Again, problem occurs at operating temp.  If it happened at a cold 500 RPM, a 400 RPM drop would = not running at all.

Oh, and the carbs were rebuilt with larger jets and the pilots adjusted, & no change

Synch speed	powered by Aeva