new sound in my engine

[Tfrank59]

So been riding the girl for about 9k since last summer and just starting to hear a new sound down there--that's never a good thing.  I'd swear it's the timing belts/tensioners, as it's very subtle and sort of drones a little at around 2k rpms.  I should mention that it's just in the past week it started, and the first time I heard it was last Sat when the temp hit 80 here.  I was wearing a half helmet and thought it was just that I had less ear coverage, but today with the 3/4 helmet I can hear it after she's been running for around 1-2 hours.  She's not overheating at all, and there's no change in performance.  Anyway, Sat when I new there was a different sound I pulled the timing cover and checked the belts and  tensioners--didn't take anything apart, just visual.  I even ran it with the cover off to watch and all looks good to me, though I'm no expert.   I'm 95% sure it's in the motor, not the wheels or what.   Anyway, I'd appreciate your ideas. Thanks.

[Bighead]

What kind of noise?

[Chrisj CMA]

could be the buzz bolt..........

[Tfrank59]

Oh, sorry, it's not a buzzing but like a faint whining noise--that's why I was thinking the tensioners--but they look okay.  it's hard to nail down better than a faint whining/droning type noise.  I might just have to get in there and change the belts (bought new ones a month ago) and check the tensioner bearings. 

[Chrisj CMA]

Oh, sorry, it's not a buzzing but like a faint whining noise--that's why I was thinking the tensioners--but they look okay.  it's hard to nail down better than a faint whining/droning type noise.  I might just have to get in there and change the belts (bought new ones a month ago) and check the tensioner bearings. 

Did you put wrenches on the buzz bolt, it cant hurt, the more you describe it, the more I think it may just be that

[SteveBC777]

Maybe something as simple, and harmless, as the fan cutting in ???

[eric in md]

put a rubber hoses to your ear and listen to your alternater...

[Bighead]

Normal Tranny whine?

[Tfrank59]

Thanks for all the replies.  100% sure it's not tranny whine; 100% not fan; 99% not buzz bolt (wrenched it hard couple days ago); I'll try listening to the alt and other peripherals.  I still think it's related to belts/tensioners, but only way to be sure it change something in there--change out belts and reset the tensioners?

[Tfrank59]

Okay as I was riding  home tonight I was really listening carefully, and it is more pronounced on the left side of the engine– But again it is a very faint new sound and it only happens when the motor's pretty warm.  but Now you got me thinking about the alternator bearings, So I was listening carefully there and even touching the cover with my glove.  But it kind of sounds like it's more towards the front of the engine – which is why I keep going back to the timing belts.  Anyways, if it is the alternator bearings Starting to go is there any definitive way to check them without pulling the alternator?  Thanks again

[Hook#3287]

It could be your timing belts are to tight.  It's amazing how much they tighten after the bike warms up.  The manual states something like 1/2" of play, don't remember the exact numbers, but it's been discussed here that that may be to tight.

I've overtightened mine a couple of times going by the service manual and had to go back and back them off some.

[Earl43P]

A $12 mechanic's stethescope might help in this situation.

I've used mine a lot, for years. Not used much on my bikes, but it gets used.

[mustang071965]

had the same thing happen last year. drove me nuts. it really sounded when i rode up into the mountains. ended up being a split in a vac line replaced the line and no more whistle.

[Tfrank59]

It could be your timing belts are to tight.  It's amazing how much they tighten after the bike warms up.  The manual states something like 1/2" of play, don't remember the exact numbers, but it's been discussed here that that may be to tight.

I've overtightened mine a couple of times going by the service manual and had to go back and back them off some.

Hook, this makes the most sense in light of what I'm hearing.  Anyways I bought the new belts like I said about a month ago so I'm just gonna go ahead and put them in.  And you're saying that the specs in the manual for the correct amount of Deflection (.2-.3) is a little too tight?  Anyways I'm going to work on my timing belts, and while I'm at it I'll check those tensioners (bearings), and then If it still makes that noise, well I know it's not my timing belts, Unless of course like you said I have to back off on the tension a little.  BTW, I do have a cheap stethoscope – and I will use it and listen to stuff.  Thanks again.

[Rio Wil]

So, what are the circumstances when you are running the engine at 2 K and hearing this noise......
Clutch in and slightly rev'ing the engine
Driving in 5 th gear at 2K rpm
Driving in 1 gear at 2K rpm

Most bikes don't spend more that a second or so at that rpm.....so what are you doing?

This engine is not silent...it has gear whine, belt tensioner noise, buzz  bolt (no matter  how tight),
calipers clunk, brake pads hiss.....etc.

[Tfrank59]

So, what are the circumstances when you are running the engine at 2 K and hearing this noise......
Clutch in and slightly rev'ing the engine
Driving in 5 th gear at 2K rpm
Driving in 1 gear at 2K rpm

Most bikes don't spend more that a second or so at that rpm.....so what are you doing?

This engine is not silent...it has gear whine, belt tensioner noise, buzz  bolt (no matter  how tight),
calipers clunk, brake pads hiss.....etc.

Keep in mind that this is a new sound to me – I've got ~ 9000 miles on her, a few hundred hours riding so I'm pretty familiar with all the normal noises You mentioned.  I can hear this best Going in second gear – so the road noise is minimal – and again it is towards the front of the engine and I noticed last night it's a bit more pronounced on the left side of the motor.  Took another ride this morning and I'm really homing in on those timing belts/tensioners now.  Just have to find the time to get in there and change them out.

[Rio Wil]

If it is the timing belts/tensioner, it will occur  standing still and simply reving the engine to 2 K.  If it requires the bike moving and in some gear...its not the belts/tensioner.  How many total miles on the bike?

Do you have a chrome alternator cover by chance?
Does the noise get louder as you are starting off from a stop and accelerate gently  through 1 and 2 gears at low  rpm.

[Tfrank59]

If it is the timing belts/tensioner, it will occur  standing still and simply reving the engine to 2 K.  If it requires the bike moving and in some gear...its not the belts/tensioner.  How many total miles on the bike?

Do you have a chrome alternator cover by chance?
Does the noise get louder as you are starting off from a stop and accelerate gently  through 1 and 2 gears at low  rpm.

You're right--shouldn't need to be moving if it's the timing belts, unless it's got to have a load on the engine?  I have the OEM chrome alt cover, and I listened in there with a stethoscope for the bearings or what and didn't hear anything rough sounding.

[Chrisj CMA]

Since it happens at a low speed it would be kinda safe to remove the timing belt cover, then go for a very short ride to the target speed and rpm.  If its the pulleys the sound should definitely be different with the cover off

[Tfrank59]

Okay, I'll give that a try.  I ran it sitting still for a few minutes on Sat with the cover off but was afraid to go for a ride like that.  I couldn't hear any different when the cover was off (in the driveway), so I put it back on and figured I was just being paranoid (like I wrote earlier, I wore a half helmet that day and thought that was the change).  Turns out it's actually a new sound but it's hard to nail down just where it's coming from and why.

[Firefighter]

I took a trip years ago and had been running expressway speeds all day. That evening in town I could hear a whine up front, speeded up and slowed with the engine speed. I was convinced my timing belt was going to break, could not enjoy myself. On my return trip I turned the music up and tried not to worry about it. Once back home I couldn't hear the noise any more, but I did change the belts, the old ones looked brand new, the bearings all seemed smooth, never knew what caused the noise. The only thing I found was the tensioner pulleys had a film of rubber on them, that I cleaned off. Never heard that noise again.

Also had a front tire whine once, especially loud on certain roads, let us know what you decide.
                                              Firefighter

[Tfrank59]

I took a trip years ago and had been running expressway speeds all day. That evening in town I could hear a whine up front, speeded up and slowed with the engine speed. I was convinced my timing belt was going to break, could not enjoy myself. On my return trip I turned the music up and tried not to worry about it. Once back home I couldn't hear the noise any more, but I did change the belts, the old ones looked brand new, the bearings all seemed smooth, never knew what caused the noise. The only thing I found was the tensioner pulleys had a film of rubber on them, that I cleaned off. Never heard that noise again.

Also had a front tire whine once, especially loud on certain roads, let us know what you decide.
                                              Firefighter

Thanks for that timely message--I was just done disassembling the belts/tensioners when I decided to get a cup of coffee and check the forum.  So I double checked the tensioners that they are clean of any film or what.  I got the belts in and all adjusted--job went like clockwork.  Took me just under 2 hours--yeah, I'm way slow, first time, yada yada.  Anyway, took her out for a short test ride--15 miles--and all seems well.  I'll have to wait to take a long ride--1 or 2 hours to get her nice and hot--to determine if the noise has been cured now.  I guess if it's not, then it's something besides the belts I was hearing, but at least now the belts are done and the tensioner bearings were like perfect, so I won't be worrying about that anymore.     Thanks again for everyone's advice.

[Bighead]

Engine will be at the same temperature after 15 minutes as 2 hours

[Tfrank59]

Engine will be at the same temperature after 15 minutes as 2 hours

Beg to differ-- the ambient air temp has a lot to do with things in your engine.  The fan kept coming on at every stop light last sat when the temp was 80 F here in seattle, and normally (when it's 55F) the fan won't come on much at all, regardless how long I'm riding or how many stops.  She was very hot and bothered that day, like mid summer, and tolerances are looser and stuff is stressed more in those conditions.

[Bighead]

Your engine should be as hot as it is going to get after 15 minutes of running no matter the outside temp. If you are low on coolant then it will get hotter but if radiator and fan working properly not gonna change over a few degrees.

[Highbinder]

I had a strange noise coming out of my engine several years ago, drove me crazy trying to find out what it was, turned out to be a couple of loose bolts on the header pipes, if I remember correctly sounded like a leaking vacuum line, you might want to check that out if your problem still exists...

[Tfrank59]

Your engine should be as hot as it is going to get after 15 minutes of running no matter the outside temp. If you are low on coolant then it will get hotter but if radiator and fan working properly not gonna change over a few degrees.

Well, my fan and rad work fine. Runs hotter in hot weather--sort of self evident.  True, not overheating but staying at the high limit of operating temp when ambient temp is high, and everything is stressed more IMO   

[Tfrank59]

I had a strange noise coming out of my engine several years ago, drove me crazy trying to find out what it was, turned out to be a couple of loose bolts on the header pipes, if I remember correctly sounded like a leaking vacuum line, you might want to check that out if your problem still exists...

Good to know.  I did check exhaust nuts as I suspected noise might be a leak under there but it's all good.   Thanks.

[Tfrank59]

So a follow up on this, I did change my timing belts last weekend, and painstakingly set the tensioners.  And I was saying earlier that with the summer like heat we had a couple weeks ago, I had a new noise which I didn't know where it came from but I suspected it was my timing belts.  Well the Mercury hit 80° again yesterday in our area, so I had her out for about 100 mile ride.  I was also wearing a half helmet like I was the first time I heard the new noise, but now it's gone.    My conclusion of course is it was the timing belts that were whining, so with the new ones in there the problem is solved and I don't have to worry about it. .   I should add that the belts I took off had no visible signs of wear or cracking or anything, so I'm not sure what to think about that.  Maybe it's just that they were getting fatigued being 17 years old?

[Chrisj CMA]

So a follow up on this, I did change my timing belts last weekend, and painstakingly set the tensioners.  And I was saying earlier that with the summer like heat we had a couple weeks ago, I had a new noise which I didn't know where it came from but I suspected it was my timing belts.  Well the Mercury hit 80° again yesterday in our area, so I had her out for about 100 mile ride.  I was also wearing a half helmet like I was the first time I heard the new noise, but now it's gone.    My conclusion of course is it was the timing belts that were whining, so with the new ones in there the problem is solved and I don't have to worry about it. .   I should add that the belts I took off had no visible signs of wear or cracking or anything, so I'm not sure what to think about that.  Maybe it's just that they were getting fatigued being 17 years old?

Well, If in fact the old belts were whining, the sound was probably due to the tensioners.  Once you changed the belts you had to re set the tensioners, and obviously you have them right if they are quiet.  Good Job