Exactly the same experience for me on my '05 ABS since I've owned it. I bought it used with 3500 miles on it and now at 6500 I'm hearing it less - but then since the weather's turned cold I'm letting it warm up a little more before taking off.I get the same sound on a hard roll off in 1st or 2nd gear, but only when the bike is cold. Once I've ridden a few minutes the sound is gone. To clarify, I'm not applying the brakes at all, just rolling off the throttle very quickly from about 4000rpm. Sounds just as everyone has described it: BBs or marbles, or tie wraps bouncing around in a metal skull...
Strange Noice During Compression Braking...
- Thread starter onecooltngeek
- Start date
Help Support Yamaha FJR Motorcycle Forum:
Sorry for reviving an old post. I bought an 05 low mileage FJR and noticed when running after only a minute or two and coming up to a stop or using engine to brake, I hear this same type noise. I was concerned about this but found this post and agree with the cat warming up reply. It does go away after a short time.
I really am enjoying this bike but feel like I'm behind the curve with a 6 yr old bike and not so many posts anymore with the old owners.
ionbeam
2 FUN
Wow, you dug up a real Zombie. Here is what is actually going on:
Until the coolant thermostat opens the Air Injection System is active which causes the noise. When the engine is cold the ECU commands the AIS to inject air into the exhaust stream for a secondary burn of the cold-run enriched exhaust fumes. The noise you are hearing is the popping from the secondary burn. Once the engine reaches operating temperature and the coolant thermostat opens the AIS is then only active when the engine is at idle.
When your engine is cold, accelerate briskly up to ~20 mph in first gear, then chop the throttle closed. You WILL hear the popping they are talking about.
Until the coolant thermostat opens the Air Injection System is active which causes the noise. When the engine is cold the ECU commands the AIS to inject air into the exhaust stream for a secondary burn of the cold-run enriched exhaust fumes. The noise you are hearing is the popping from the secondary burn. Once the engine reaches operating temperature and the coolant thermostat opens the AIS is then only active when the engine is at idle.
When your engine is cold, accelerate briskly up to ~20 mph in first gear, then chop the throttle closed. You WILL hear the popping they are talking about.
Last edited by a moderator:
RadioHowie
I Miss Beemerdons!
The definitive answer is "backfiring in the headers on a cold motor."
The Air Injection System is injecting fresh air into the exhaust because the motor isn't warmed up to full operating temperature. The ECU is running a richer mixture because the motor is warmed up...etc. Fresh cold air hits richer mixture in exhaust headers = backfiring. Lots of little, bitty backfires.
You hear the noise coming from the front of the bike for two reasons....that's where the headers are, and the big-*** (stock) mufflers on an FJR do their job REAL well, i.e., muffling.
Remove the PAIR system and the problem goes away forever.
Edit: I see the REAL Einstein posted before me.
The Air Injection System is injecting fresh air into the exhaust because the motor isn't warmed up to full operating temperature. The ECU is running a richer mixture because the motor is warmed up...etc. Fresh cold air hits richer mixture in exhaust headers = backfiring. Lots of little, bitty backfires.
You hear the noise coming from the front of the bike for two reasons....that's where the headers are, and the big-*** (stock) mufflers on an FJR do their job REAL well, i.e., muffling.
Remove the PAIR system and the problem goes away forever.
Edit: I see the REAL Einstein posted before me.
Last edited by a moderator:
Thanks for the info. I really appreciate it. It definitely is coming from the front but sounds more like something is rattling around than a pop or backfire. But like I said, this is a new bike to me so everything is a learning process.
ionbeam
2 FUN
Revision B --
If the noise is heard only with a cold engine and during deceleration my first and primary suspect is the Air Injection System. Do force the noise as described earlier and see if it matches what you are hearing. Given the situation you describe I strongly suspect the noise is from the AIS being active and we just have a failure to communicate how the noise sounds. If the noise is definitely not the same then read on...
There are a few rare '05 engines that experience premature valve guide wear due to excessively tight stem seals starving the guides of lubrication. This noise will almost always start at the upper left (clutch) side of the engine. The only sure check, per Yamaha, is to pull the exhaust header and look for oil residue. Your FJR will continue to run fine and will always get you home. Over tens of thousands of miles it will gradually get worse and oil consumption will start to go up. This is not a panic problem like the CCT.
There is one other thing that can cause this kind of noise but I didn't want to panic anyone. Many Gen I engines have an inadequate Cam Chain Tensioner (CCT) which does not have the strength to take out all the cam chain play resulting in a rattling noise heard at the right side timing cover. If you have a rattling noise in this area you need to have the CCT replaced ASAP. There is a new CCT design, identified by a blue dot and this should be the only CCT that you can buy. There have been some engines that have suffered catastrophic cylinder head damage due to the CCT so don't take this noise lightly. If the cam chain is rattling the CCT has failed because as long as the CCT is good you will not hear the rattling noise.
Please do yourself a favor and either you or your shop listen and confirm where the noise is coming from if it is not the AIS. You can use a real mechanic's stethoscope to listen to the timing cover and the exhaust header for noise or 'make' one of you own. You can use a long screwdriver or better, any long metal rod then with a fully warm and idling engine put the rod on the timing cover then put your ear to the rod. You will be amazed at what you can hear. Next, go to the left side of the engine and then through the faring openings, press the rod on a header tube and listen for a noise described as silverware being rattled in a drawer. In this Forum the noise is called The Tick or Ticking -- do a search there are even sound clips of the noise.
I really hope the noise you hear is the the AIS, followed by The Tick. Best luck!
Edit: Corrected a massive amount of typing and formatting errors
If the noise is heard only with a cold engine and during deceleration my first and primary suspect is the Air Injection System. Do force the noise as described earlier and see if it matches what you are hearing. Given the situation you describe I strongly suspect the noise is from the AIS being active and we just have a failure to communicate how the noise sounds. If the noise is definitely not the same then read on...
There are a few rare '05 engines that experience premature valve guide wear due to excessively tight stem seals starving the guides of lubrication. This noise will almost always start at the upper left (clutch) side of the engine. The only sure check, per Yamaha, is to pull the exhaust header and look for oil residue. Your FJR will continue to run fine and will always get you home. Over tens of thousands of miles it will gradually get worse and oil consumption will start to go up. This is not a panic problem like the CCT.
There is one other thing that can cause this kind of noise but I didn't want to panic anyone. Many Gen I engines have an inadequate Cam Chain Tensioner (CCT) which does not have the strength to take out all the cam chain play resulting in a rattling noise heard at the right side timing cover. If you have a rattling noise in this area you need to have the CCT replaced ASAP. There is a new CCT design, identified by a blue dot and this should be the only CCT that you can buy. There have been some engines that have suffered catastrophic cylinder head damage due to the CCT so don't take this noise lightly. If the cam chain is rattling the CCT has failed because as long as the CCT is good you will not hear the rattling noise.
Please do yourself a favor and either you or your shop listen and confirm where the noise is coming from if it is not the AIS. You can use a real mechanic's stethoscope to listen to the timing cover and the exhaust header for noise or 'make' one of you own. You can use a long screwdriver or better, any long metal rod then with a fully warm and idling engine put the rod on the timing cover then put your ear to the rod. You will be amazed at what you can hear. Next, go to the left side of the engine and then through the faring openings, press the rod on a header tube and listen for a noise described as silverware being rattled in a drawer. In this Forum the noise is called The Tick or Ticking -- do a search there are even sound clips of the noise.
I really hope the noise you hear is the the AIS, followed by The Tick. Best luck!
Edit: Corrected a massive amount of typing and formatting errors
Last edited by a moderator:
Revision B --
If the noise is heard only with a cold engine and during deceleration my first and primary suspect is the Air Injection System. Do force the noise as described earlier and see if it matches what you are hearing. Given the situation you describe I strongly suspect the noise is from the AIS being active and we just have a failure to communicate how the noise sounds. If the noise is definitely not the same then read on...
There are a few rare '05 engines that experience premature valve guide wear due to excessively tight stem seals starving the guides of lubrication. This noise will almost always start at the upper left (clutch) side of the engine. The only sure check, per Yamaha, is to pull the exhaust header and look for oil residue. Your FJR will continue to run fine and will always get you home. Over tens of thousands of miles it will gradually get worse and oil consumption will start to go up. This is not a panic problem like the CCT.
There is one other thing that can cause this kind of noise but I didn't want to panic anyone. Many Gen I engines have an inadequate Cam Chain Tensioner (CCT) which does not have the strength to take out all the cam chain play resulting in a rattling noise heard at the right side timing cover. If you have a rattling noise in this area you need to have the CCT replaced ASAP. There is a new CCT design, identified by a blue dot and this should be the only CCT that you can buy. There have been some engines that have suffered catastrophic cylinder head damage due to the CCT so don't take this noise lightly. If the cam chain is rattling the CCT has failed because as long as the CCT is good you will not hear the rattling noise.
Please do yourself a favor and either you or your shop listen and confirm where the noise is coming from if it is not the AIS. You can use a real mechanic's stethoscope to listen to the timing cover and the exhaust header for noise or 'make' one of you own. You can use a long screwdriver or better, any long metal rod then with a fully warm and idling engine put the rod on the timing cover then put your ear to the rod. You will be amazed at what you can hear. Next, go to the left side of the engine and then through the faring openings, press the rod on a header tube and listen for a noise described as silverware being rattled in a drawer. In this Forum the noise is called The Tick or Ticking -- do a search there are even sound clips of the noise.
I really hope the noise you hear is the the AIS, followed by The Tick. Best luck!
Edit: Corrected a massive amount of typing and formatting errors
The noise is only when the engine is cold for the first few minutes. I think is the first AIS scenario. When I was shopping for my bike I test rode another 05 with "the tick". It is definitely not the same sound. I've also noticed that my throttle response is also very 'on and off' during the same time period and then goes away once warmed up. Probably not related but thought I'd throw it out there.
Again, thanks for the expertise.
This is too funny. I read all the way through from the beginning of this zombie and my immediate reaction was: "Hey I know what that is. It's the PAIR system."
But then I continued on and saw that Professor ionbeam already grabbed the brass ring.
I think what's actually happening is that the PAIR solenoid is activating, which opens up the path from the air-box to the ports on the top of the cylinder heads. What you are hearing is the reed valves flapping in those ports in the head, not the combustion in the exhaust pipes.
To test this theory all you would need to do is disconnect the electrical connector that goes to the PAIR solenoid. Just leave everything else hooked up. Since the solenoid will never open you should no longer hear the ticking noises. This is completely safe to do. Many of us have removed the PAIR plumbing altogether and replaced the ports with block off plates.
edit - what's funny is that nobody seemed to come up with the right answer back in 2005!!
But then I continued on and saw that Professor ionbeam already grabbed the brass ring.
I think what's actually happening is that the PAIR solenoid is activating, which opens up the path from the air-box to the ports on the top of the cylinder heads. What you are hearing is the reed valves flapping in those ports in the head, not the combustion in the exhaust pipes.
To test this theory all you would need to do is disconnect the electrical connector that goes to the PAIR solenoid. Just leave everything else hooked up. Since the solenoid will never open you should no longer hear the ticking noises. This is completely safe to do. Many of us have removed the PAIR plumbing altogether and replaced the ports with block off plates.
edit - what's funny is that nobody seemed to come up with the right answer back in 2005!!
Last edited by a moderator:
ionbeam
2 FUN
BBBZZZZTTTTT take a seat :lol: The Air Injection Solenoid is turned OFF by the ECU when 12V is APPLIED to the solenoid. Unplugging the solenoid would mean that the noise would be present all the time because the solenoid spool would be open all the time. You would almost think that Yamaha did that to keep someone from unplugging the solenoid to disable the system
I also reread the whole post and thought the same thing. It just goes to show how the Forum has grown and matured as a source for complete and accurate information. ptschuma says thanks for the expertise when in fact it may just be the result of sticking around for >5 years reading all the **** things people have written. The quality of the information that we have banked away here is what makes the Collective so good.
After I answered the first post in 5 years I was going to quip that the question is answered and being Friday it's time to derail the thread and get into armadillos, aardvarks, sheep and manatees like seems to happen to most threads.
Hmm... good catch. I didn't consider that.
But that means that unplugging the thing would still prove the hypothesis. With the PAIR solenoid unplugged it won't stop buzzing on decel when the engine is warmed up. However, I'm not sure how well the cat would like this...
I think once you know what the Strange Noice (sic) you should be able to quit worrying about it.
Or get these.
But that means that unplugging the thing would still prove the hypothesis. With the PAIR solenoid unplugged it won't stop buzzing on decel when the engine is warmed up. However, I'm not sure how well the cat would like this...
I think once you know what the Strange Noice (sic) you should be able to quit worrying about it.
Or get these.
Last edited by a moderator:
nevermind
Last edited by a moderator:
ionbeam
2 FUN
Uh-oh, we've been caught agreeing :huh: And, you are right, the cat may choke on a steady diet of air from the Air Injection System. Actually the word slag comes to mind.
russperry
Well-known member
I too have heard this noise, or at least something that sounds similar to your description. It does seem to be most obvious when cold, in fact I'm not sure if I've ever heard it once the bike's up to normal operating temps. In my experience its worst in 1st gear, but that may be because wind noise is lower so any other noise is more noticeable.
