R3T cyclical hiss

[Anomaly]

Ok, I'm at a loss here. I need someone smarter than me to help.

My bike just started exhibiting a cyclical hiss and deceleration backfire. I thought it was a loose sparkplug at first, but all 6 are nice & snug. The sound cycles with the engine and sounds like it's coming from between the rear 2 cylinders. I pulled up the tabk and looked all over as well as sprayed soapy water all over looking for bubbles to indicate a leak, and don't see anything.


I figured if it wasn't a loose plug, then perhaps a leak in a vacuum line, but I can't find a leak or crack in a vacuum line anywhere.


The bike is a 2015 R3T with 42K miles, and it has a RamAir kit fitted to the intake. Not sure that makes a difference, but looking for any suggestions on where I might be able to find this new hiss.

I recorded a short (1 min) audio clip, where you can hear the hiss, idk I guess I'm hopin' someone else is somewhat familiar with this.

SndUp | R3T hiss

Record, upload, share! SndUp is a social network, for audio! We enable you to upload audio clips and share them with the world. Sharing your talent is simple!

sndup.net

 

[rainman]

Have you checked the connection on the coil packs

 

[Anomaly]

Have you checked the connection on the coil packs

From the sparkplug to the coil packs? Yes. I. Hecked the tightness of each plug, the reseated the coil packs and made sure they had a good connection.

 

[Kevin frazier]

Did you pull each plug out and inspect? Up out of the hole. if not i would suggest that. Also the caps on the spark plug wires that screw onto the coils will crack and if they crack theyre not tight even when bottomed out. i would put in new plugs regardless they are cheap and if the tune has been off as in that backfiring you explained is too much fuel somewhere in map. when was ram air installed and has any recent work been done. I know you said a smart person but it’s Saturday and they wont be back till Monday so I thought id throw a few things at you that they may need to know. Except for Rainman i see he mentioned those coils

 

[Gerald]

Ok, I'm at a loss here. I need someone smarter than me to help.

My bike just started exhibiting a cyclical hiss and deceleration backfire. I thought it was a loose sparkplug at first, but all 6 are nice & snug. The sound cycles with the engine and sounds like it's coming from between the rear 2 cylinders. I pulled up the tabk and looked all over as well as sprayed soapy water all over looking for bubbles to indicate a leak, and don't see anything.


I figured if it wasn't a loose plug, then perhaps a leak in a vacuum line, but I can't find a leak or crack in a vacuum line anywhere.


The bike is a 2015 R3T with 42K miles, and it has a RamAir kit fitted to the intake. Not sure that makes a difference, but looking for any suggestions on where I might be able to find this new hiss.

I recorded a short (1 min) audio clip, where you can hear the hiss, idk I guess I'm hopin' someone else is somewhat familiar with this.

SndUp | R3T hiss

Record, upload, share! SndUp is a social network, for audio! We enable you to upload audio clips and share them with the world. Sharing your talent is simple!

sndup.net

Check the vacuum hoses and caps at the throttle bodies.

 

[Anomaly]

Did you pull each plug out and inspect? .... Except for Rainman i see he mentioned those coils

The backfiring started with the hiss. The map is custom from a dyno tune. It's been flawless until today. I just checked the plugs to make sure they weren't loose. I probably should replace the plugs bc yea they are so cheap.

 

[Kevin frazier]

sounds like its idleing good just that hiss.

 

[Frans]

catalytic converter still on the bike? If so check if it is not melted/blocked

 

[Anomaly]

catalytic converter still on the bike? If so check if it is not melted/blocked

No, the cat has been gone for years.

 

[Gregger]

That sounds like a vacuum leak. A vacuum leak will give you a leaner mixture especially on deceleration which will cause decel popping/backfiring. Do you have tune ecu and a cable? If you perform a cylinder balance check the leaking vacuum line should affect the reading on one cylinder more than the others.