Bike is making loud banging/knocking noise

[Guest Gibbyrgibson 79]

Hi all,

My NC700x 2013 is making a loud knocking noise. It's not too bad when cold. However, when warned up it gets progressively worse. It also gets worse at the beginning of acceleration. I have recently held the clutch in and it stops when I do this.

 

I'm new to biking and this is my first bike. It's done 25000 miles. 

 

Any advice would be much appreciated.

Edited April 29, 2019 by Gibbyrgibson 79
Wrong model imputed.

[KingJames 1,262]

Does your service history show the valves being checked/adjusted? 

What type of oil is in it? 

[steelhorseuk 1,690]

First thing that comes to mind on a NC700 manual with 25k on the clock making that kind of noise "loud knocking" is a loose or worn Cam Chain or tensioner.

I suggest you get it in for inspection as it may do more damage if you keep riding it.

Edited April 29, 2019 by Steel Horse UK

[Guest Gibbyrgibson 79]

Not sure to both. I can advise when I get home to the oil. 

[KingJames 1,262]

Where in the world are you?

[Guest Gibbyrgibson 79]

Not sure on the relevance of that to the question. 

[ted 5,734]

The fact that it stops the noise when holding in the clutch makes me want to concentrate on the drive train clutch assembly.

[KingJames 1,262]

Suggestions of getting a known good local mechanic to give you a steer on what it is likely to be.  Reason for my two questions above are they are based around a hot engine, Mark's is generic and all are very possible.

 

South coast and South London, I can give you a steer to one.

[Guest Gibbyrgibson 79]

1 minute ago, KingJames said:

Suggestions of getting a known good local mechanic to give you a steer on what it is likely to be.  Reason for my two questions above are they are based around a hot engine, Mark's is generic and all are very possible.

 

South coast and South London, I can give you a steer to one.

I live in Newcastle. Theres a Honda garage near by. Or should I do my homework on which garage first?

11 minutes ago, KingJames said:

Does your service history show the valves being checked/adjusted? 

What type of oil is in it? 

 

10 minutes ago, KingJames said:

Does your service history show the valves being checked/adjusted? 

What type of oil is in it? 

 

[KingJames 1,262]

Maybe labour rates up near you are reasonable but it pays to do so down my way.  Also mechanic competence, does your Honda dealer have a good reputation for being able to fix things not just sell bikes and overcharge for an oil change?

[sid 227]

If the noise goes when the clutch is pulled in, could be a knackered release bearing, or loose / damaged clutch basket?

[trisaki 2,029]

Clutches rumble a bit , but wouldn't call it knocking  , does it ride ok , no vibrations through  the  bike  , has the clutch  lever got any free play  ,

[sid 227]

25 minutes ago, trisaki said:

Clutches rumble a bit , but wouldn't call it knocking  , does it ride ok , no vibrations through  the  bike  , has the clutch  lever got any free play  ,

They can deffo knock if the basket is naffed.

Think we can eliminate big ends, cam chains etc if it goes with the clutch in. Only other possibilities is maybe one of the bearings on a gear shaft.

[Guest Gibbyrgibson 79]

I have noticed my chain is a little slacker than normal, could it be chain whip, only a guess. I'm going to tighten it the see if it stops. If not I'm booking it in this week. Will keep you all posted, thanks for the advice.

[sid 227]

Chain should not cause a knocking noise. However, some noises I appreciate are quite hard to explain.

[embee 7,288]

Simplest question is what is the oil level?

Should check the oil with the bike upright and the dipstick resting on the threads, not screwed in. As long as it's between the max/min marks that's OK for a start.

 

Have you looked at the gearbox sprocket? Easy to remove the cover, on mine it's 2 bolts, I assume the other models are essentially the same. Here's a guide

 

Worn, sometimes the teeth are missing altogether is badly neglacted

Edited April 29, 2019 by embee

[Grumpy old man 4,670]

1 hour ago, Gibbyrgibson 79 said:

I have noticed my chain is a little slacker than normal, could it be chain whip, only a guess. I'm going to tighten it the see if it stops. If not I'm booking it in this week. Will keep you all posted, thanks for the advice.

Don't over tighten the chain. I live in Prudhoe if you ant to bring it round I'll have a look with you but I'm no expert.

[thanosgp 3]

If the timing chain tensioner is damaged, you can notice the noise when you rev the throttle. When rpm is going down, the chain usually slap on the casing. Very disrinctive and particular noise. As suggested i would check if the chain has to much slack or is worn out/stretched/ has tight spots.Please dont forget to adjust the free play of  clutch  cable on the spot that is attached to the basket
 

[DaveM59 1,603]

You would hear a timing chain at idle and on blipping the throttle on the stand.

Same with any engine bearings, you could hear it when not moving although the fact that it is quieter when cold (thicker oil) could point to big or little end bearing(s). Does the oil pressure light go out quickly on start up and has this been an issue since last oil change or before? 

If it only does it when moving it has to be transmission related and pulling the clutch silences it at speed, so it's not the chain as that continues to turn with the wheel so it has to be clutch or gearbox related and possibly front sprocket.

Try using a sounding rod placed to your ear and pressed against various parts of the engine/gearbox casing to see if you can pinpoint the source of any funny noises (like a stethascope).

[SteveThackery 3,090]

Surely the fact that it disappears when the clutch is pulled in precludes anything to do with the engine?  Having said that, the engine can't generate any torque when the clutch is pulled in, so it could still be mains or big-ends, especially if you can modulate the noise with the throttle.

 

To be honest, though, I think a mechanic or an informed owner needs to look at it for you.  It is almost impossible to diagnose noises via text conversations.  

 

Is there any way you can record a video* of it on your phone and post it?  If not here, then on YouTube?  Move the phone around so we can hear where it seems to be coming from.  Also, demonstrate the effect of blipping the throttle and pulling/releasing the clutch.

 

*PS: I don't mean while you are riding!  

 

 

 

Edited April 30, 2019 by SteveThackery