Low RPM Chatter under load ~ 1800 to 2500 rpm

[cpd3020]

Hello,

My Valk IS is making a chattering noise between say 1800 and 2500 rpm while under load (or going up hill, etc).  Sounds like it's coming from up front somewhere.

I tried to search the forums for a direct answer to this and it got covered once before:

http://www.valkyrieforum.com/bbs/index.php/topic,7748.0.html

But the owner didn't post what it ended up being (his description is exactly what mine is doing....)   There were tons of suggestions but nothing definitive.

Anyone had this issue and know what the fix is?  I just got the bike a couple months ago and have been doing maintenance on it.  I do not believe it has been desmogged yet.

Thank you in advance!
Shane

[Hook#3287]

Shane, sounds like your going the right direction by following the suggestions in the old post.  I'd do the de-smog first.  Easy change is going to high test gas if your running reg.

Sometimes, first or low number posters don't get back to the board with their results.  Most likely, he followed one of the suggestions , solved his issue and never returned.

[sandy]

You don't say the mileage on your bike. Could it be the cam tensioners rattling due to loose cam belts? Desmogging won't fix this issue. Our bikes build torque at about your RPM (1800). Maybe downshift until you can sort this a bit better.
BTW: My Tourer has 75 ft/lbs at 2200 RPMs.

[Chrisj CMA]

Depends how on how much a load you are talking about.  If it's doing it in 5th gear and hard acceleration, then that sounds normal to me.

[Firefighter]

We don't know how much chatter you are hearing? All Valks make a noise while under load, the gears are square cut they are noisy. So I don't know if that is what you are hearing or if it is detonation from a bad tuned engine. I can even feel a slight vibration from the gears but only under load.

[cpd3020]

To answer a few questions I have about 84k miles, have been using premium gas.  I took it for a 3 hour ride yesterday with my wife on board.  Probably 400lbs between the both of us.

I really heard it at lower rpms a couple times when going up hill under load.  Down shifting seems to fix it with the higher rpms.  Just not used to the noises its making yet.  I got caught in a higher gear on a "suprise hill" after a curve.

Rear suspension was bottoming out too so i stopped and bought a spanner wrench and found the previous owner has one rear shock on 5 and the other on 1....  that was easy to fix... lol

[Firefighter]

If downshifting fixes the problem, maybe you are to slow for the higher gear while climbing the hill.

example: 1800 rpm in 4th or 5th gear while two up climbing a hill is going to cause clatter.

Not trying to be a smart ass either, just trying to understand. You should not need premium fuel.

[3W-lonerider]

if you have trans covers, might wanna look at this.
http://www.valkyrieforum.com/bbs/index.php/topic,57770.0.html

[Hook#3287]

Went back and read the original post you listed.

Looks like the poster was leaning towards an exhaust leak.

He has an email listed in his profile, maybe you could send him a note asking how he solved his issue.

[Paladin528]

I have had this exact issue since I got the bike last spring.  I have not nailed it down yet.
I have done a few things in the course of regular maintenance since I got it.
Exhaust Gaskets replaced - No difference.
Regular - Premium - Fuel no difference (Back to Regular)
Replaced fuel feed lines and removed inline filter  - No difference
(However did note that the fuel line does travel uphill the way it is routed.  I will address this.)
Timing Belt tensioners checked and are fine
New Plugs - no difference.
Of course New coolant and oil - no difference as expected

Next on list.
Carb sync
Possibly a desmog.

The sound is distinctively like detonation and only occurs at lower RPMs during Acceleration.  Yes running at higher RPMs lessens it but the issue exists right from a first gear launch

[3W-lonerider]

yep and the link I posted to sounded like detonation to. that's why it was so hard to track down.

[Paladin528]

I have run it naked with the same result.  Just can't track it down

[Steel cowboy]

Have you checked the infamous "buzz bolt" mine was making a racket at about the same RPM.
It's the long bolt behind the radiator pods that goes thru the pod mounting bracket to the other side of the bike. It's about 12 inches long.
 I purchased another bolt so I could torque down the crap out of it and if it cracked I'd have a spare. It worked.

[DarkSideR]

My mike has done the same as yours since day 1. I have gone round, and round, and round with trying to find the cause of the noise, but to no avail. In addition to what you have done, and looked into I have sync'd carbs, as well as advanced the timing with a trigger wheel, and use premium fuel. Thinking it was an exhaust leak I replaced the exhaust header gaskets and regularly check the header bolts to make sure they hadn't come loose.

My bike has been desmog'd, so it isn't the pair valves.

So here is what I think it is. My dad desmog'd the bike, and in doing so used freeze plugs. I think one of those freeze plugs has a leak. I haven't taken the time to replace the freeze plugs, but am admittedly putting it off because if that doesn't fix it then.. well the only other thing it could be is the internal oil chain has slack in it and makes noise under load. I can't image what it takes to replace that.

And so my story ends with.. I have to accept the fact that my bike makes noise. The only good advice I have been given is to get louder pipes so I don't hear it.

And FOR THE LOVE OF GOD if you figure this one out PLEASE POST THE FIX!!!!

[Paladin528]

I actually induced the Buzz Bolt issue while trying to narrow it down.  COMPLETELY different sound.
My bike is not desmogged so thats not the issue. 

[Patrick]

I'd be concerned about detonation/spark knock. If the 'chatter' is coming from the engine, I'd do what can be done to figure whether it is spark knock or not. Since you are using premium grade fuel, I'm concerned about a lean condition [ o-rings, etc] and what trigger wheel it has.

These monsters should accelerate from a high idle in top gear with out issue or noise.

Its hard to diagnose such a problem in a forum such as this. A 'chatter' can mean different things to different people. Exhaust leaks can be a royal PITA to correct, but, they can be heard best under light acceleration.

Some of these critters have a 'tick' that just can't be found/fixed. Some have thought it is the oil pump chain and they could very well be right.

When all is said and done, I'd do what I could to make sure it isn't detonation.

[Ricky-D]

It most likely is driveline chatter since you are not able to locate the source. Driveline chatter can emit from any

number of possible locations and be caused by looseness of many items due to poor maintenance and/or wear.

***

[CajunRider]

Have you checked the infamous "buzz bolt" mine was making a racket at about the same RPM.
It's the long bolt behind the radiator pods that goes thru the pod mounting bracket to the other side of the bike. It's about 12 inches long.
 I purchased another bolt so I could torque down the crap out of it and if it cracked I'd have a spare. It worked.

+1 on that "buzz bolt".  Tightening that puppy made mine quiet as can be. 

But don't worry about cracking or breaking it.  I probably put over 100 ft-lb on it before it just wouldn't turn anymore (I put everything I had pulling on a standard sized ratchet). 

Of course, I only weigh in at 170 lbs... so everything I had may not have been all that much.    

[wild6]

I had a chatter under low rpm load that got worse to the point that it started doing it at idle.
Listened closer and I heard it coming from the alternator. (Felt it there, too)

Removed the alternator and found that the nut on the end of the shaft was loose.

[The emperor has no clothes]

I had a chatter under low rpm load that got worse to the point that it started doing it at idle.
Listened closer and I heard it coming from the alternator. (Felt it there, too)

Removed the alternator and found that the nut on the end of the shaft was loose.

I had that issue recently also.

[DarkSideR]

I had a chatter under low rpm load that got worse to the point that it started doing it at idle.
Listened closer and I heard it coming from the alternator. (Felt it there, too)

Removed the alternator and found that the nut on the end of the shaft was loose.

I had that issue recently also.

Does the alternator need to be removed to check the nut?

[gordonv]

Yes. Alt needs to be removed to check everything, except the voltage output.

[The emperor has no clothes]

I had a chatter under low rpm load that got worse to the point that it started doing it at idle.
Listened closer and I heard it coming from the alternator. (Felt it there, too)

Removed the alternator and found that the nut on the end of the shaft was loose.

I had that issue recently also.

Does the alternator need to be removed to check the nut?

yeah 

[DarkSideR]

Good news! The low rpm chatter I am experiencing is not due to a loose alternator nut. Bad news! I did not resolve the low rpm chatter I am experiencing. Also on a short ride today I noticed I can now here the chatter at 55mph. I am either insane and the noise really isn't there, or I will soon be going insane.

Sigh..

[DK]

Do you have one of the stamped metal "Valkyrie" or such radiator covers?

Two years ago I had a noise similar to what you describe. This possibility occurred to me while stopped for lunch so I stuffed a small wad of napkins into the top and bottom edges of the cover to hold it away from the radiator. It stopped the noise.

I've since replaced the napkins with a small rubber foot attached to the back of the cover that pushes the cover away from the radiator. It stops the vibration noise and aids cooling efficiency by holding the solid parts of the cover away from the radiator core so as to allow air to more freely circulate thru the core.

Dan

[DarkSideR]

Do you have one of the stamped metal "Valkyrie" or such radiator covers?

Two years ago I had a noise similar to what you describe. This possibility occurred to me while stopped for lunch so I stuffed a small wad of napkins into the top and bottom edges of the cover to hold it away from the radiator. It stopped the noise.

I've since replaced the napkins with a small rubber foot attached to the back of the cover that pushes the cover away from the radiator. It stops the vibration noise and aids cooling efficiency by holding the solid parts of the cover away from the radiator core so as to allow air to more freely circulate thru the core.

Dan

Dan, yes I do have a cover and have physically held it while the engine idles to no avail. I have tightened, and probed just about everything.

I once had a Suzuki Bandit. The cam chain stretched on that bike so much that the tensioner had no more adjustment in it. I could hear the cam chain slap around inside the engine. I eventually tore that engine down and replaced the chain.

The noise I hear on the Valkyrie reminds me of the cam chain noise I heard on that old Suzuki. I know the Valkyrie doesn't have cam chains, just trying to describe the sound I hear. I very positive it's coming from inside the motor.

I got rather excited when I read a couple posted on the the possibility of having a loose alternator nut. Darn was I bummed when I found the nut to be tight as could be.

[Ricky-D]

The oil pump is a "chain drive" unit, and located deep inside the engine.

***

[DarkSideR]

The oil pump is a "chain drive" unit, and located deep inside the engine.

***

I was told early on the oil pump chain could be the cause of the clatter, and I am pretty sure that's what it is because I have checked (literally) everything else. I however can't find any documented instances of anyone else having oil pump chain problems.

Maybe it's time to take it to The Attic Rat, hoping that while he is in there doing his thing the oil pump chain could be looked at/replaced.