But when I pull up to stop lights, sometimes - and not all that often, but sometimes, I hear a rather loud crunching sound. I think it's when I have the clutch pulled in, but not 100% sure it doesn't happen in neurtral too. Engine will be running fine, idling where it should, then I hear this crunching sound but it doesn't change the idle at all. Seems to still be running fine, and takes off and runs great, no issues. Just this intermittant sound when stopped at lights.
Any thoughts?
Bike has 26K miles, oil is good, no idot lights, runs fine, acceleration strong, etc....
Definitely take a look at your chain. I had something like that on my Wee that I couldn't figure out during the tail end of a long tour.. got worse and worse until it sounded like the rear end was going to crack off. The chainrings were quite shark-tailed and the chain was stretched out. Once swapped, it went away and all was well.
I have a 2000, 26k miles, new sprockets and chain and perfectly good clutch at 24.5k, this noise has been with me since 24.0k when I bought the bike
When I have the clutch part way out, I'm in the process of using it before it is all the way in or out, I hear a noise that reminds me of someone wadding up a piece of celephane, like a hard candy wrapper
I don't know how else to explain it, it sounds electrical, but the bike shop has never figured out what it is, and the clutch works just fine, and the noise does not seem to be coming from the actual clutch lever or clutch lever joint on the handlebar
Hmmm. Interesting replies so far. My noise happens only when I'm stopped at a light, so it's definitely not the chain. If I had to guess before better research on my part, I'd say it sounds like the gearbox. I had a K1200RS a while back and although my bike did not exhibit this sound, they were well known for "sounding like a box of rocks" when shifting through the gears. You could only hear it at low speeds though, so in city traffic, it sounded like, well, a box of rocks. I know this because I test drove several before I bought one.
This sounds different, but does remind me of that. I'll pay better attention when I'm out riding this weekend to whether the clutch position plays any part. I do ride with full face helmet and ear plugs so it's not always that easy to tell where sounds are coming from. And I could not replicate it in my driveway.
We'll see. Keep coming with the ideas. It is interesting that similar sounds seem to be "out there" among us.
Oh, and I never get the noise when the clutch is all the way out, or all the way in, it only happens when the clutch lever is being squeezed to disengage the clutch, or letting go of the lever to engage the clutch, it happens in that middle point for me
[image: View Post]TripleH, on 05 June 2012 - 10:00 PM, said:
Oh, and I never get the noise when the clutch is all the way out, or all the way in, it only happens when the clutch lever is being squeezed to disengage the clutch, or letting go of the lever to engage the clutch, it happens in that middle point for me
That's the flapper on the airbox whap-whap-ing open and closed. If it really annoys you disconnect and plug the vacuum line under the tank.
Add me to the list that hears the sound of cellophane while sitting at a light. A crackling noise that i noticed for the first time about 2 weeks ago. It sounded electrical and sort of freaked me out. Seemed to come from the dash panel but i have not taken that apart to look. I usually ride with ear plugs and that certainly masks the noise.
I'll be more observant related to the clutch. It was probably engaged.
[image: View Post]vfrcapn, on 05 June 2012 - 10:18 PM, said:
[image: View Post]TripleH, on 05 June 2012 - 10:00 PM, said:
Oh, and I never get the noise when the clutch is all the way out, or all the way in, it only happens when the clutch lever is being squeezed to disengage the clutch, or letting go of the lever to engage the clutch, it happens in that middle point for me
That's the flapper on the airbox whap-whap-ing open and closed. If it really annoys you disconnect and plug the vacuum line under the tank.
[image: View Post]vfrcapn, on 05 June 2012 - 10:18 PM, said:
[image: View Post]TripleH, on 05 June 2012 - 10:00 PM, said:
Oh, and I never get the noise when the clutch is all the way out, or all the way in, it only happens when the clutch lever is being squeezed to disengage the clutch, or letting go of the lever to engage the clutch, it happens in that middle point for me
That's the flapper on the airbox whap-whap-ing open and closed. If it really annoys you disconnect and plug the vacuum line under the tank.
Please note this is ONLY valid for 5th-gen VFRs. The 6th-gen flapper is operated on completely different parameters (specifically engine vacuum and engine speed, not just engine speed).
Oh, and I never get the noise when the clutch is all the way out, or all the way in, it only happens when the clutch lever is being squeezed to disengage the clutch, or letting go of the lever to engage the clutch, it happens in that middle point for me
That's the flapper on the airbox whap-whap-ing open and closed. If it really annoys you disconnect and plug the vacuum line under the tank.
This.
My thought as well. Unplug the vacuum line, then stick a bolt or something in that line to plug it up. Then see if you hear your noise.
[image: View Post]vfrcapn, on 05 June 2012 - 10:18 PM, said:
That's the flapper on the airbox whap-whap-ing open and closed. If it really annoys you disconnect and plug the vacuum line under the tank.
Wow, cool, seems like several others agree with ya
Now, can someone explain this in more detail to me, I'm a rider, NOT a mechanic.
I know how to get to the airfilter, and can change it, but that is about all... Is this just a characteristic, and not a real problem?
Where is this flapper, how can I find it?
Where is this vacuum line, how can I find it?
[image: View Post]MarkDetroit, on 05 June 2012 - 10:33 PM, said:
A crackling noise that i noticed for the first time about 2 weeks ago.
It sounded electrical and sort of freaked me out.
Seemed to come from the dash panel but i have not taken that apart to look.
The brain trust may have found our noise, and it seems like it's not electrical
I totally hear ya about the freeking out, I know I have several times when I have heard this
Had the same noise/problem. Found that my clutch switch was going south and it made the noise worse as the switch would not make good contact throughout the clutch stroke. The slightest movement of the clutch handle at a stop light would make the flapper open/close. New switch, about $6.00 from Mason City and no more noise at all. It did sound like a crunching noise from under the tank and sometimes the front fairing before I fixed it. Hope this helps.
[image: View Post]huntinggunns, on 06 June 2012 - 09:35 AM, said:
Had the same noise/problem. Found that my clutch switch was going south and it made the noise worse as the switch would not make good contact throughout the clutch stroke. The slightest movement of the clutch handle at a stop light would make the flapper open/close. New switch, about $6.00 from Mason City and no more noise at all. It did sound like a crunching noise from under the tank and sometimes the front fairing before I fixed it. Hope this helps.
[image: View Post]TripleH, on 06 June 2012 - 09:44 AM, said:
[image: View Post]huntinggunns, on 06 June 2012 - 09:35 AM, said:
Had the same noise/problem. Found that my clutch switch was going south and it made the noise worse as the switch would not make good contact throughout the clutch stroke. The slightest movement of the clutch handle at a stop light would make the flapper open/close. New switch, about $6.00 from Mason City and no more noise at all. It did sound like a crunching noise from under the tank and sometimes the front fairing before I fixed it. Hope this helps.
That is the one. The switch itself would also making a crunching noise when the plunger was pressed in after it was pulled off. I know of a couple of other members that have had the same problem. Here is an example of what the noise sounds like.
Simple to replace. IIRC there is just 1 screw holding the switch in. Unplug the 2 wires, unscrew the switch screw, remove the old switch and place the new one in its place, put a dab of blue locktite on the screw before re-installing the screw, and plug the 2 wires back on. Takes about 5 minutes. Also, don't stress about which wire goes to which terminal of the switch. If you forget which one goes to which terminal on the switch, just remember, it is a loop and the switch is just completing the circuit.
[image: View Post]huntinggunns, on 06 June 2012 - 10:13 AM, said:
[image: View Post]TripleH, on 06 June 2012 - 09:44 AM, said:
[image: View Post]huntinggunns, on 06 June 2012 - 09:35 AM, said:
Had the same noise/problem. Found that my clutch switch was going south and it made the noise worse as the switch would not make good contact throughout the clutch stroke. The slightest movement of the clutch handle at a stop light would make the flapper open/close. New switch, about $6.00 from Mason City and no more noise at all. It did sound like a crunching noise from under the tank and sometimes the front fairing before I fixed it. Hope this helps.
That is the one. The switch itself would also making a crunching noise when the plunger was pressed in after it was pulled off. I know of a couple of other members that have had the same problem. Here is an example of what the noise sounds like.
http://www.vfrdiscus...tch#entry597254
I had the same noise problem that drove me nuts. After replacing the switch the problem is solved.
If you want to get at the flapper valve, it's right on top of the airbox. Take the seat off, remove the two front bolts holding the tank on and swivel the tank up. The vacuum line running on top of the airbox goes right to a solenoid, pull it off and plug it up with something handy. No need to open the airbox up, shouldn't take more than 10 minutes. I believe this will leave the flapper in the open position.
I'm just catching up to this thread - THANKS!! This is definitely the noise I'm hearing. I'll read through the other referenced thread as well. If we disconnect the vacuum tube and the flapper valve is then left open, what is the affect on the engine / running / acceleration? I guess in other words, what does the flapper valve do and when? I take it the quick open / close is NOT functioning properly, or is that as designed? And how would the clutch lever switch be connected to the flapper valve?
Supposedly the flapper valve, according to Honda literature, is there to promote better intake airflow at differing rpm ranges.
Coincedentally, the flapper valve is closed at the speeds/rpms That the EPA mandated drive by noise test is performed at. You do the math.
I have totally removed the intake snorkel, flapper valve, and actuator, and have. OT had a sleepless night since. Nor have I wondered why my bike is such a dog under 5,000 rpm. (it's not)
For the rest of the tribe: it's your bike, run it the way you want.
End of thread · 27 posts recoveredWayback Machine snapshot 9 Jun 2012