Weird noise - 6th to 5th downshift

[pkelly20]

2017 ES - 3,000 km.
When I’m cruising along at 100 km/h or more, let off the throttle and blip to downshift from 6th to 5th, I hear this weird flutter noise. Almost like a turbo blow off valve dumping boost. I don’t know how else to describe it. Does anyone else hear this noise? Is it normal?


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[2daMax]

No I do not hear those noise when downshifting. Do you hear it if you are on idle and rev high and let go?

 

[Nikolajsen]

Me niether...
Only from 6th to 5th? and not from 5th to 4th? (and so on)

 

[Xclimation]

I'm pretty sure I know what noise you are referring to. Is it a hissing or whooshing noise almost sounding like pressure is being equalized or something like that?
Both my 2012 and now my 2015 both make that sound. I can't pinpoint when it does but I'm pretty sure it was when I sometimes downshift.
If it's the same sound you are talking about, then I believe (not sure) it is the fuel pump. The reason why I think it is because it makes close to the same sound when turning the key to start up the bike. Only when it does it while riding it seems to be a little louder. But I am curious to know for sure. Sometimes the sound last longer. I'm going to try and keep track of when it does this. Especially with respect to what temp the bike is showing, speed, if after a downshift, etc.

 

[pkelly20]

I know the sound the fuel pump makes when first turning on the key. It’s not that sound. My bike only does it when I shift down from 6 to 5th. Not between any others and never on upshift.


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[Nikolajsen]

Very strange ???
I have no idea :'(

 

[Don in Lodi]

Don't blip the throttle. Try down shifting normally and see if the noise is still there.

 

[RonH]

I agree. Blipping not needed unless riding a Harley.

 

[pkelly20]

I agree. Blipping not needed unless riding a Harley.

Blipping to rev match on the downshift is what I should have said. The shifts are smoother that way, less wear on the clutch. I’ll try it without the throttle blip to see if the noise is present or not.


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[Dogdaze]

Blipping to rev match on the downshift is what I should have said. The shifts are smoother that way, less wear on the clutch. I’ll try it without the throttle blip to see if the noise is present or not.


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::026:: Especially on a downhill winding mountain road where rear wheel torque lock-up is not a good thing.

 

[Don in Lodi]

::026:: Especially on a downhill winding mountain road where rear wheel torque lock-up is not a good thing.

I knew there was something wrong with my bike. I don't have near that kind of decel on this bike. I even asked Anthony if there was some way for him to increase the decel. All these riders talking about tuning down their decel. I need to rake down two, even three gears to get the bike anywhere close to chirping the back tire. The modern syncros in todays trannys are not susceptible to the rev issues of earlier tractor tech.

 

[Dogdaze]

I knew there was something wrong with my bike. I don't have near that kind of decel on this bike. I even asked Anthony if there was some way for him to increase the decel. All these riders talking about tuning down their decel. I need to rake down two, even three gears to get the bike anywhere close to chirping the back tire. The modern syncros in todays trannys are not susceptible to the rev issues of earlier tractor tech.

I agree, but as we don't run slipper clutches in the S10 yet, I have had a few impending lock ups when downshifting 2 gears (5th to 3rd), not even fast, just unexpected tight bends (my bike has a lowly 4300kms)
Anyway, sorry to interrupt the thread ::008::

 

[pkelly20]

Just got back from a 2 hour ride. Tried dropping from 6 to 5th with and without rev matching with the throttle. The sound is there either way.

I think it’s easier to hear when rev matching because the intake noise isn’t as loud. If I drop from 6th to 5th without rev matching the intake noise and maybe the transmission whine tends to hide the noise.

I think I’m hearing intake flutter, but it’s got a slight metallic ring to it. Only does it from 6th to 5th.


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[Dogdaze]

I would lift the tank, open the air box and check it is seated correctly and secure. May be that air is being sucked in from a gap. One place to start.

 

[2daMax]

I would check the air box for 3 areas just to make sure nothing is odd. These are related to acoustical noise.

1. Air intake temp sensor installed correctly at the RHS.
2. Engine vents linking to the bottom of the air box, if that hose is secured both ends.
3. Throttle body boots clamp, if they are tight.

Also, for the final drive, when was the last time the oil was checked or changed. There is a breather vent on the Final Drive. Would that noise somewhat comes from the left rear side?

 

[WJBertrand]

Some good points on checking the air box. Check also that all the lid screws are seated and the lid is properly sealed. My ST1300 was making some strange noises (though they at least sounded intake related) and I discovered the shop I'd had it to recently had stripped out most of the screw holes on the housing base. The screws could no longer be tightened, most had worked loose, and a few were missing. Like the Super Tenere, they just screw directly into the plastic. Be careful not to overtighten.

As a side note I discovered the Super Ten's airbox lid screws are just slightly larger than the Honda ones. I ordered a package of them and they worked perfect to re-cut threads in the Honda airbox and tightened down nicely! Noises gone.

 

[pkelly20]

Hi Everyone,

Thanks for all the responses.

Update: My 17 ES model now has around 4,000 km on it and still makes the noise although it seems to be a little quieter now.

Since I first made this thread I have done the following:

Throttle body sync. This gave me the chance to open the air box and have a look inside. Everything looked great and the airbox lid screws were definitely all tight.

I didn’t notice any loose sensors or clamps and the tank vent lines were all in their correct guides down to the bottom of the bike.

My final drive oil was changed at 1,600 km when I performed the second oil change.

I still blip throttle on downshifts because it’s smoother that way and my right hand just does it. I try to do it less abruptly because as others have said it doesn’t seem to like snappy throttle inputs with the clutch pulled in.

I think the noise I’m hearing is the transmission whine but it’s slightly different sound because of the rev matching. Imagine the normal whine when you downshift without rev matching. But instead of the continuous whine it’s abbreviated and intermittent but repeating at high frequency as a result of the rev match. So the transmission is right on the verge of being loaded and unloaded in deceleration.

I will report back in a few thousand as the bike continues to break in.


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[Wrathchild]

I agree. Blipping not needed unless riding a Harley.

Maybe not needed but still smoother and better pretty much all around. Less syncro wear, smoother deceleration etc. There is a reason so many non-harley bikes do it automatically when they sense pressure on the shifter in a downshift sort of way.

 

[WJBertrand]

I thought we (and most motorcycles) had constant mesh as opposed to synchromesh transmissions. The parts diagram for the transmission does not show the presence of any traditional synchronizer cones or rings like you would see in an automotive manual transmission.

https://www.partzilla.com/catalog/yamaha/motorcycle/2015/super-tenere-es-xtz12efcr/transmission

Not sure what the noise is in the Tenere, but I know in a car you can hear the synchros working when you have a large differential between input and output shaft speeds and try to change gears.

 

[Sierra1]