Horrible Noise Under Acceleration.

[TOM VR46]

   Well here goes. Went to work yesteday and engine felt wee bit rough. Felt like chain needed tightening, but had been done previous week.
Finished work, fired bike up ,, no problems,, into first and off i go,, ,,,, felt like engine sprocket had came loose.
Very slow acceleration , noise still there going up gears. Cruising at 50 ish and felt ok.
Stop at junction,, oh no problems going down gears,, pulled away and felt like someting grinding,, only under pressure.
So far,, no play in rear wheel,, chain ok,, engine sprocket ok,, upgrade done on that some time ago. Tickover no noise. Goes through gears ok.
Thats as far as time will allow me till week end. Oh high millage on engine. And clutch done last year.
Any ideas very welcome. Wont get time now till sunday , but suggestion will be greatfull and followed.
Off to work, on four wheels  .
oh,, couldnt tell which side noise coming from.

[darrsi]

You say you tightened the chain last week.
I'd be looking at that again, as it sounds possible to me that it's too tight and maybe also misaligned.
Put the bike on the centre stand, and spin the rear wheel backwards. It should make a purring noise if the chain tension is good and the wheel is straight.
If the chain is too tight then you'll hear and probably see that it isn't right, and if it's misaligned it will make a consistent clunking sound as it tries to correct itself. 
The chain should just about comfortably touch the plastic chain guide that's near the front sprocket when you raise the bottom line of it.


To do all this correctly you need to nudge the wheel forwards and gently bring the wheel back either side using the nut at the back of the swingarm. Don't forget to loosen the caliper tension bar otherwise the right side will not budge.
The notches on the swingarm should be a good guide for either side, but are not always 100% correct plus obviously every bike is different, which is why i find spinning the wheel until it purrs nicely works better in my opinion. You may need to nip up the main wheel bolt before you can attempt to spin it properly though. It's all about doing it gradually, then once you're happy with it you won't need to touch it again for ages once all the locking nuts are tightened too.


On a side note, if i am correct and it is a simple tension/misalignment thing then it's a real quick way of wrecking a chain and sprockets if it's not sorted out promptly.
Bear in mind i'm talking about a chain in decent nick too, if it's dry or has stuck links then that will just make matters feel much worse.
You can check for stuck links by looking at the bottom row of the chain, if any are not totally horizontal then it's not a good sign, although when links are stuck you'll normally feel them bumping through your left footrest.

[Gnasher]

Check the front sprocket.  These are typical symptoms of a worn lay shaft thread/nut. These will look and feel ok as the sprocket runs on the splines, but the shaft is destroying the loose nut thread.  The sprocket is end floating on the lay shaft but is held in place by the sprocket cover.  You need to remove this cover takes minutes. 

[TOM VR46]

Wee update. Got an hour this evening to into shed.
Onto paddock stand and checked rear wheel , chain sprocket and looked for any play. Nothing. Chain has done much millage , new Febuary this year. But i  did slacken and redo chain tension. All good and straight.
So engine sprocket,,, cover off and all good. To be honest this is where i was expecting trouble but i did upgrade on sprocket nut a while ago. Again i was spinning rear wheel and looking and listening for anything,, nothing. Played around with sprocket and couldnt feel anything , play or roughness.
So fired up and into gear while on stand,, and all good. There was the usual chain jumping a bit but nothing out of ordinery. Used my foot to put pressure on rear wheel (not recommended if you are wearing good boots) ,, nothing.
One last wee thing to try for night,, off stand,, into gear ,, front brake and see how she pulls. It would quite happily put me through side of shed,, but no grinding noise,, ahh ,, good or bad ,dont know.
So tomorrow ill take wee spin to see whats happening when im on the move. Time for a beer and some head scratching.

[fazersharp]

So you have checked the sprocket nut with a tourque wrench is that it is right ?But you can not do this without removing the locking tab washer - so is it possible that the shaft is spinning inside the sprocket when under load - nasty noise.
When the sprocket was done with the upgraded nut what tourque was it done to and was there the correct lock tight applied or even the right one.
Other than that you said that the clutch was replaced - others more expert on that subject will help but I think you can have problems with wrong springs or fitting it wrong or somthing.

[darrsi]

Now i'm thinking that you just need to properly adjust your clutch cable, from the bottom end first, then tweak at the top. Only takes a minute to do with the correct tools (buy yourself a deep offset ring spanner)
Is the cable very old, maybe it's time for a new one?



And if you ever put the bike into gear on the centre stand the chain will always jump about due to wheel momentum trying to overtake the engine speed.
If you VERY GENTLY use the throttle the engine will then pull the chain and wheel and smooth things out.

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[TOM VR46]

Well, as i said take for wee spin today,,, and i will be honest i didnt think i would make it to end of street. Even said to a friend i was just going to take it round block to see if i could tell more what side noise was coming from. Took it easy and went approx 10 miles ,, no noise. I stopped a couple of times just to put some pressure on it ,, nothing hard just smooth up gears. Nothing. So im stumped.

Happy yes, but i will say i was covering clutch and brake all way , just in case.

• Sprocket nut was well torqued up , cant remember what it is without looking it up and locking tab in place. But with all posts ive read , with the noise and feeling i was sure it had came loose. But all tight and no movement.
• Clutch cable and movement all good. Clutch plates are maybe just over a year old. Changed them just because of mileage , old ones were'nt too bad, still got them somewhere.
• So next just to be curious im going to drain oil. Cant remember if ive got magnet on sump plug but will drain and see if any thing in there and will take cover of and have wee look in at clutch. Didnt get time for that today , would have been great to have done it as engine was warm.
• Well big thank you for listening to me and replies. And ideas.  I will just take it easy when on her and see what happens,  Fingers crossed .  I will let you know if oil is clear and condition of clutch side.
• Friend thinks im mad riding her , but cant tell anything with it sitting in shed.

Thanks so far. Catch in a bit.

[unfazed]

Missed this as I have not been on here with a week. It is very possible you had a small stone stuck in the brakes or sprocket area, makes an incredible racket as if the the bike is going to fall to bits. First happened many many years ago coming out of Birmingham and I though the bike was was going to fall apart and it was a two month old 400 four Honda.  Stopped on the side of the motorway to have a look andfound nothing wrong pushed the bike back and forward a few times to see where the noise was coming from. No sound, decided to start the bike and then rode off very cautiously and it was running perfectly. Never had any issue afterwards it baffled. When I got home I was saying it to a mechanic and he said it was most likey a small stone. stuck somewhere.However I would remove the wheels and check the bearings to be safe

[TOM VR46]

   Well i was just about to agree with you unfazed ,but its back again. Took bike to work last night , taking it easy all good. When i say easy , just cruise mode, maybe not above 5ooo on revs.
Finished about half 4 this morning , roads quiet. Again not pushing it but maybe a bit more going up gears and it didnt feel good again. I would definetly say low gears , first up to third, fourth. Fifth and sixth not so bad and cruising about 60 not bad. But stop or slow down and pull again and its there. Definetly more of a grind , not a thumping but hard to say what side. Thats whats getting me at moment i cant say from where. And feeling is from both sides.
So going to have to give this more time and thought. Definetly going to have a look at clutch side,, just time i dont have much off. 

[darrsi]

Seeing as we're no wiser, what about the front brake calipers?
If they were seized up your pads might be worn to the metal, holding the bike back and causing the grinding sound?

[Gnasher]

Check the front lay shaft bearing for play/noise.  These can and do wear/dry out mainly due to overtightening the drive chain.

It's also possible one or more of the gearbox bearings has had it.

Ignore the the brake caliper comment.   They will just bind or tick, excessive brake dust, you'll feel resistance/loss of performance and possible blueing of the disc/s in extreme cases.  What you're describing is drive/transmission issues.

Check the wheel alignment, the rear sprocket carrier bearing, rear wheel bearings these can dry out with no play.  Also check every link in the chain, then check swing arm and shock linkages.

[darrsi]

Check the front lay shaft bearing for play/noise.  These can and do wear/dry out mainly due to overtightening the drive chain.

It's also possible one or more of the gearbox bearings has had it.

Ignore the the brake caliper comment.   They will just bind or tick, excessive brake dust, you'll feel resistance/loss of performance and possible blueing of the disc/s in extreme cases.  What you're describing is drive/transmission issues.

Check the wheel alignment, the rear sprocket carrier bearing, rear wheel bearings these can dry out with no play.  Also check every link in the chain, then check swing arm and shock linkages.

Erm, excuse me?
We don't know what's wrong yet,  including you, so how about any idea is a possibility, and appreciated, eh?

[Grahamm]

Can I please remind people to keep things courteous when trying to help another member sort out a problem, thanks.

GrahamM - Moderator

[BBROWN1664]

Ignore the the brake caliper comment.   They will just bind or tick, excessive brake dust, you'll feel resistance/loss of performance and possible blueing of the disc/s in extreme cases.  What you're describing is drive/transmission issues.

(for now) as the OP has said at a constant speed the noise isn't there , just when accelerating. If it was the calliper the noise would potentially be different as speed increases but wouldn't stop when you stop accelerating.

As the noise appears to only be there as speed is being increased, you need to look at things that are only affected by increased load. Chain, sprockets, output shafts and alignment of all of these things (wheel alignment). Looking at brakes would be VERY low on the list.

[darrsi]

Ignore the the brake caliper comment.   They will just bind or tick, excessive brake dust, you'll feel resistance/loss of performance and possible blueing of the disc/s in extreme cases.  What you're describing is drive/transmission issues.

  (for now) as the OP has said at a constant speed the noise isn't there , just when accelerating. If it was the calliper the noise would potentially be different as speed increases but wouldn't stop when you stop accelerating.

As the noise appears to only be there as speed is being increased, you need to look at things that are only affected by increased load. Chain, sprockets, output shafts and alignment of all of these things (wheel alignment). Looking at brakes would be VERY low on the list.

Would take seconds to check them out and eliminate them though, no harm done?

[TOM VR46]

Thanks for all replies. Didnt get the time i wanted this weekend due to work. But had another tinker around , really wanted to drain oil and pull clutch but no time.   I did see possible and only possible slight movement in swing arm. If there was it was as i say very slight.
But took wee spin and im definetly thinking lay shaft , drive shaft area now. Its getting bad pulling away, Tick over fine, into first fine. Clutch out and it feel rough. Up gears and will settle when crusing , down gears ok. Start again and it cross fingers nothing breaks,  up to 3rd , pull clutch in and let her roll, all fine, just free wheels ,, let clutch out and it rough , definetly in drive area.
To be honest , if you felt what i was feeling pulling away,,, you wouldnt sit being me,, not close anyways.
So again thanks , and will keep update on where i go from here,,, time allowing.

[basher]

I think you should definitely drop the oil just to be sure man, if the internals are making strange sounds its most likely metal on metal contact somewhere in there and any contact isnt good for the engine. it could be a cheese grater in there 

I know personally rn because my camshafts were destroyed after my mistake... replacing the head now live and learn lol

[unfazed]

Just a suggestion, but needs care and two people when doing it.Try simulating acceleration with the bike of the centre stand foot on the brake and bike in whatever gear it sounds worse in open the throttle a bit that will put pressure on the bearing and allow you to locate wher the noise is coming from.Anytime i have had to do this it is on a lift tied down

[darrsi]

Just a suggestion, but needs care and two people when doing it.Try simulating acceleration with the bike of the centre stand foot on the brake and bike in whatever gear it sounds worse in open the throttle a bit that will put pressure on the bearing and allow you to locate wher the noise is coming from.Anytime i have had to do this it is on a lift tied down

If you're gonna do this it might be worth seeing if the noise can be recorded in case it becomes obvious to the right ears.
Maybe put a video on YouTube so it can be viewed and listened to if you manage to recreate the sound.

[jack_lee]

Is there any updates?