WTF is this clunking noise?

[dcstrom]

Engine knock. Mine does it too. This motor has no knock sensor. Only does it under heavy load at lower revs. Usually several knocks close together.

Thanks Epping - that's really what I'm looking for. Despite the title of the thread, I don't really expect a diagnosis, I really just want to know if others have heard the same noise. If "they all do that" I'm not going to worry about it.

When I first heard it I wondered if it was some weird form of pinging - I mentioned on a thread elsewhere here. My experience with pinging though has always been as a rattling sound - not the "clunk clunk" I'm getting here.

The other reason I was concerned is that I'm taking off to South America and beyond later this year. If I was staying in the US I would just get the extended warranty and keep riding. However the warranty doesn't cover the bike outside the US and Canada - so if it IS something to worry about, I want it dealt with before then.

The main reason I made the video was so that I could have something concrete to show Yamaha. Because it's fairly infrequent I have my doubts that it would do it if the tech took it for a ride.

So I guess Yamaha will either have an answer, or want to look at it further, or at least I will get it on record if I need to make a claim later. That's my thinking anyway!

Here's the full sequence - I had to do two "laps" to get it to make the noise. You can see my Pedrosa-like precision riding on display (ha ha I'm a legend in my own lunchtime - as Barry Sheene used to say about Max Biaggi). There is very little difference in line and speed each time through the corner, but the first time I don't get the knock, the second time I do. I may have hit the gas just a little harder the second time.

I'm hoping this is how "pinging" manifest itself on this bike - it's good to be able to recognize it when it happens! I'm running mid-grade on this particular tank, so if pinging that may be a contributing factor. But I've had it with premium as well.


clunklong

 

[Yamaguy55]

Do you always run the proper fuel grade? Or have engine mods that would enhance excessively lean condition? The twin plugs per cylinder are there to enable it to resist knocking, but without a knock sensor, if you lean it out any more by either improving intake or exhaust flow, it will be stoopid lean and prove it to you.

 

[dcstrom]

Do you always run the proper fuel grade? Or have engine mods that would enhance excessively lean condition? The twin plugs per cylinder are there to enable it to resist knocking, but without a knock sensor, if you lean it out any more by either improving intake or exhaust flow, it will be stoopid lean and prove it to you.

I MOSTLY run the proper fuel grade, but with a trip to Sth America coming up, I want to know how it's going to react to lower grades, so I run them on occassion. As far as I can tell the incidence of knocking doesn't change much - if at all - with different grades of fuel. I guess what I have to do is find a situation that is repeatable - and go try it with different grades of fuel, preferably in the same weather conditions...

No mods, but planning on switching to either a K&N or foam Unifilter (stock in the Oz bikes) soon. Not sure which yet!

 

[stevepsd]

No mods, but planning on switching to either a K&N or foam Unifilter (stock in the Oz bikes) soon. Not sure which yet!

Foam. Especially if you will see any dirt or dusty roads. K&N's are ok for street but let in to much fine dirt for off-road use.

 

[Epping]

As far as I can tell the incidence of knocking doesn't change much - if at all - with different grades of fuel.

No mods, but planning on switching to either a K&N or foam Unifilter (stock in the Oz bikes) soon. Not sure which yet!

I have Leo Vince & foam filter & run 95 octane but it does this also on 98 as well. Just the nature of the beast I guess. This is not good for the engine, but the occasional knock I guess will not reduce the life of the bike to any measurable degree. Doesn't seem to matter if in S or T either. I just don't lug the engine and keep the revs up ::26::

 

[Yamaguy55]

I MOSTLY run the proper fuel grade, but with a trip to Sth America coming up, I want to know how it's going to react to lower grades, so I run them on occassion. As far as I can tell the incidence of knocking doesn't change much - if at all - with different grades of fuel. I guess what I have to do is find a situation that is repeatable - and go try it with different grades of fuel, preferably in the same weather conditions...

No mods, but planning on switching to either a K&N or foam Unifilter (stock in the Oz bikes) soon. Not sure which yet!

I find the K&Ns ok, but the trick is to NOT clean them, but reoil from the clean side once in a while. The original intent of these way back in the the dim past, was to avoid the clogging of the paper ones, and the foam one as well. The foam ones just took longer to clog. Years ago, (and I've already received flak for this statement: so believe it or not, your choice) I had a DT3 while in a very dry and dusty place. The stock Yamaha foam element would require cleaning weekly. The Filtron foam replacement would last a bit longer, so I finally gave in and switched to a K&N. I knew even then that they aren't ideal when clean, so I minimized my heavy dust runs until I had some amount of build up on the filter, then reoiled from the inside, and I got over 35K from that crankshaft, so it couldn't have leaked too much dirt. I also found it flowed so much more air that rejetting was mandatory. I did a road run one day with no filter at all, and the jetting was still spot on. Therefore, in that application, the K&N had the same airflow as no filter. Not surprising: the old DT had a 30 or 32mm Mikuni, so I'm sure the surface area of the K&N was much more than necessary. Those old A/C two strokes didn't much like lean conditions. I finally cleaned the filter when I sold the bike, and at that point, you could barely still see the pleats through the caked dust. The trapped dirt actually aids in filtration; you just need to keep reoiling from the clean side so it doesn't dry out.

If you're worried about engine damage from intake debris, just buy several stock filters, toss them when they become dirty. If you go with the pods, be sure the breather hole in the airbox to the engine has some form of filtration, otherwise you're just sucking dirt though the oiling system. It is one of the hoses on the bottom of the airbox, going in from the clean side of the filter. That's the air that goes through the engine to purge blowby for the PCV system, or our version of it. From y viewpoint, being concerned with dirt in the combustion chamber and ignoring dirt being added to the lubrication system is not an improvement.

As for knocking: maybe an ECU reflash and a PC with several fuel/ignition maps are in order for your upcoming globe trotting. Cheaper than new pistons and crankshafts. Gas outside of the US is sometimes spotty in grade/quality. I know the Tenere is billed as a world traveler, but crap gas is crap gas. Those are very large diameter pistons, and it is diameter and end gasses that cause the grief with knocking. Add 11:1+ compression and 50 octane gas and you're in for real fun. Even my '97 F150 requires 89 octane or better around here in winter for no pinging up mountain roads. Just a thought.

 

[Tremor38]

I find the K&Ns ok, but the trick is to NOT clean them, but reoil from the clean side once in a while. The original intent of these way back in the the dim past, was to avoid the clogging of the paper ones, and the foam one as well. The foam ones just took longer to clog. Years ago, (and I've already received flak for this statement: so believe it or not, your choice) I had a DT3 while in a very dry and dusty place. The stock Yamaha foam element would require cleaning weekly. The Filtron foam replacement would last a bit longer, so I finally gave in and switched to a K&N. I knew even then that they aren't ideal when clean, so I minimized my heavy dust runs until I had some amount of build up on the filter, then reoiled from the inside, and I got over 35K from that crankshaft, so it couldn't have leaked too much dirt. I also found it flowed so much more air that rejetting was mandatory. I did a road run one day with no filter at all, and the jetting was still spot on. Therefore, in that application, the K&N had the same airflow as no filter. Not surprising: the old DT had a 30 or 32mm Mikuni, so I'm sure the surface area of the K&N was much more than necessary. Those old A/C two strokes didn't much like lean conditions. I finally cleaned the filter when I sold the bike, and at that point, you could barely still see the pleats through the caked dust. The trapped dirt actually aids in filtration; you just need to keep reoiling from the clean side so it doesn't dry out.

If you're worried about engine damage from intake debris, just buy several stock filters, toss them when they become dirty. If you go with the pods, be sure the breather hole in the airbox to the engine has some form of filtration, otherwise you're just sucking dirt though the oiling system. It is one of the hoses on the bottom of the airbox, going in from the clean side of the filter. That's the air that goes through the engine to purge blowby for the PCV system, or our version of it. From y viewpoint, being concerned with dirt in the combustion chamber and ignoring dirt being added to the lubrication system is not an improvement.

As for knocking: maybe an ECU reflash and a PC with several fuel/ignition maps are in order for your upcoming globe trotting. Cheaper than new pistons and crankshafts. Gas outside of the US is sometimes spotty in grade/quality. I know the Tenere is billed as a world traveler, but crap gas is crap gas. Those are very large diameter pistons, and it is diameter and end gasses that cause the grief with knocking. Add 11:1+ compression and 50 octane gas and you're in for real fun. Even my '97 F150 requires 89 octane or better around here in winter for no pinging up mountain roads. Just a thought.

Regarding the reflash, I would probably have ECUunleashed flash my ECU for the lowest possible octane (least amount of timing advance) if I planned to spend any significant amount of time riding in third-world countries...JMHO.

 

[dcstrom]

Regarding the reflash, I would probably have ECUunleashed flash my ECU for the lowest possible octane (least amount of timing advance) if I planned to spend any significant amount of time riding in third-world countries...JMHO.

Thanks guys - NOW you tell me, when my farkle budget is all used up!

Actually there are a number of Sth American Tenere owners on the forum, and I've been taking note of their posts about this issues. No real problems that I've seen, but I'll check with them directly.

Then there's the Nick Sanders example too - through south america 3 times and ZERO engine damage on stripdown.

 

[Epping]

Then there's the Nick Sanders example too - through south america 3 times and ZERO engine damage on stripdown.

Exactly. ::021::

 

[528Hz]

I have had this knock on both teneres during hard acceleration only, in the 2nd and 3rd gears, regardless on fuel grade. nothing to do with steering bearings.

 

[Kevhunts]

I have had this knock on both teneres during hard acceleration only, in the 2nd and 3rd gears, regardless on fuel grade. nothing to do with steering bearings.

Try it with the traction control turned off and see it the noise is still there.