K&N Crickets?

[norseman]

I'm sure this has been covered elsewhere, but I couldn't find anything specific when I searched.

I just got my bike back with the K&Ns under the bearclaw and a PC5. The bike runs great, much less decel popping. There is a notable chatter from the K&Ns at certain revs. Is this the "cricket" noise that is spoken of so frequently with the air mod? I like the sound of it, to be honest. I just want to verify that it's not something off that needs to be addressed.

Also when I stopped for my first fuel-up the gas cap was SUCTIONED into the tank. I had to give it a bit of a tug and there was a pressure release sound when it came up and out. I'm mildly concerned because I don't want the fuel pump to have to work too hard to draw fuel out.

So are the chattering sounds from the K&Ns just "crickets"?
Should I be worried about suction in my fuel tank?

 

[TriumPhil]

It's the sweet sound of your throttle bodies...

 

[cardinal93]

I think multiple people get and describe the sounds differently! I think it depends on the side too.
As for the suction on the tank, I didn't experience that?? I am opening the tank a little more ( down to 32 mpg), but no hard suction with it. I'm sure someone smarter will come along, but I might try putting a pinhole vacuum release in the gasket ring, if nobody else offers a better solution

 

[scot in exile]

You say much less decel popping? are you still running lean might be time for a new tune.

 

[Mittzy]

I would have thought the tank would have some kind of breather!
Do you have a manual? Can download from the net.

 

[tdragger]

The crickets are the sound of immense power being made.

As far as the gas cap, prior to changing out the whole assembly, the gas cap would not close properly if I didn't give it a good firm push. Then the suction situation would occur. The inference is that you need to make sure the cap is closed securely for the vent to work properly.

Also, if whoever mounted the K&N's had to raise your tank, they could have pinched the vent tube when they lowered the tank.

 

[Rocket Scientist]

The tank should never have suction on it. If air can't get in, fuel can't get out. Could cause a catastrophic lean condition at high speeds. I wouldn't wait to get that sorted. I'm not sure how the vent system works, I know there are two small lines that run from the bottom of the tank down under the left side cover. Like was mentioned earlier, I would check those for kinks, pinches, etc.

 

[HansO]

The crickets are the sound of immense power being made.

As far as the gas cap, prior to changing out the whole assembly, the gas cap would not close properly if I didn't give it a good firm push. Then the suction situation would occur. The inference is that you need to make sure the cap is closed securely for the vent to work properly.

Also, if whoever mounted the K&N's had to raise your tank, they could have pinched the vent tube when they lowered the tank.

The tank should never have suction on it. If air can't get in, fuel can't get out. Could cause a catastrophic lean condition at high speeds. I wouldn't wait to get that sorted. I'm not sure how the vent system works, I know there are two small lines that run from the bottom of the tank down under the left side cover. Like was mentioned earlier, I would check those for kinks, pinches, etc.

as both the above have said and it something that needs to check urgently! It is possible that when lowering the tank after doing the work the Tech may have pinch a breather line there are two lines that run from near the front band back along the left side of the tank, I suggest you lift the tank and make sure they are in their keepers and not getting fouled against the frame and tank at the rubber mounts. Also while you have the tank up pull the hoses of one at a time and make sure you can blow air thru them one is a overflow from the filler area the other is a breather to inside the tank, it wouldn't hurt to get a short length of tube and blow in to the fittings under the tank just to make sure a bug has not found its way in there and caused a blockage

 

[CanberraR3]

I quite like the 'crickets' and certainly got used to them.

I'd say there's no doubt the breather hose from you fuel tank is pinched or blocked. Easy fix either way and, as others have said, do it now.

 

[barbagris]

So are the chattering sounds from the K&Ns just "crickets"?
Should I be worried about suction in my fuel tank?

The cricket noise - is imo due to resonances in the inlet tracts. May even be a bit of spit-back. Personally I don't like it - enough in fact to remove the K&Nś.

However since Hanso's new PCV tune has removed all vestiges of decel-popping - I'm tempted to retry - though I'm more tempted to try using the OEM rubber "bell-mouths" and ITG filters.

The tank suction/vacuum issue - GET IT SEEN TO.