[leontan505]

I got a 2008 CBR600RR and i recently noticed when I am decelerating, I can faintly hear a knocking sound that sounds almost similiar to a rod knock sound. I cannot be totally sure as i do not hear anything when it is idling. Could it be a misfiring issue cause by bad plugs or ignition coils?

If it helps, when I throttle the bike above 3k RPM the bikes somehow sounds like a V-engine? but when it gets in the upper RPM band it sounds alright.

Any inputs on this or experience with this you guys had?

 

[leontan505]

Link to video for sound

2008 CBR600RR Knocking sound on decelerating

Any inputs will be appreciated

 

[NewRedRider]

Welcome to the net!

I'm really struggling to hear anything abnormal. When is the last time you oiled (not chain wax) and adjusted your chain? How does the bike run in the higher RPM ranges above 10k? Have you inspected your wheels, wheel bearings, brake calipers, etc. for tightness or abnormal wear?

 

[dannoxyz]

Greetings & Salutations!!!

1. do compression test, post numbers here

2. post pics of all spark plugs

3. send injectors in for flow-testing & cleaning Mr Injector

 

[NewRedRider]

Greetings & Salutations!!!

1. do compression test, post numbers here

2. post pics of all spark plugs

3. send injectors in for flow-testing & cleaning Mr Injector

Do you hear something?

 

[dannoxyz]

Do you hear something?

Slight unevenness on decel.
Could be worn-out chain & sprockets.
Worn-out cam-chain or tensioner.
Might be uneven cylinder firing due to blown headgasket (sucks in coolant on decel).

 

[leontan505]

Hi everyone, thanks for your inputs, I have changed a new set of chain, sprocket, tyres, front and rear wheel bearings, brake pads, rotors are smooth and not warpped. Unforturnately the place I am living at doesnt give me the convenience to open up the entire bike =( Oh I am using a APE manual tensioner and have set the tension when I changed all the wear and tear listed above.

There isnt any leakage that i noticed when I took ut the side fairings and belly pan. Only a small leak from the Oil Sight glass.

I am bringing the bike to my mechanic later on. WIll update when he gets back to me.

 

[leontan505]

I do not think it is a head gasket or coolant leak as well as my engine oil drains out really healthly. Doesnt look like "chocolate milk" which indicates a headgasket leak or bad water pump seal. So I have narrowed it down to the rod bearings or misfiring. Well gotta see what my mechanic says

 

[tary preisser]

In vid, I hear that v twin sound on decel, it's at like 4-3krpm and decel on closed throttle....?
With my poor understanding of these bikes maybe its minimal fuel on full closed throttle at very low rpm's causing that misfire sound?

 

[leontan505]

Mechanic has checked and test ridden the bike. Thankfully it wasn't a rod knock as he says usually if it is the case of a bad rod, it will be easily heard upon just idling. It was probably the exhaust. He narrows it down to a badly balanced throttlebody and suggesting to do a compression test on my next oil change. Still pending shipment of my oil sight glass so will do everything in one shot when it arrives.

 

[tary preisser]

Throttle body set at factory.

If your mechanic can rebalance, please let us forum members know how?

Thanks!

 

[leontan505]

Throttle body set at factory.

If your mechanic can rebalance, please let us forum members know how?

Thanks!

I will update once it is all done as my mechanic is busy with many bikes at the moment. Will get him to further check on my ignition coild and sparkplugs while he is at it. Just want a peace of mind as well since he will be going down to the throttlebodies I figured why not check on the plugs and all as well

 

[tary preisser]

Good to be thorough, I found my Cali '09 to be a little rough and have abrupt throttle response under 3K rpm and small throttle......I blamed California's restrictive emissions requirements.

I don't ride the bike in places where I've got to doddle along (like in slow traffic), so not really a concern...

 

[toRRa]

I got a 2008 CBR600RR and i recently noticed when I am decelerating, I can faintly hear a knocking sound that sounds almost similiar to a rod knock sound. I cannot be totally sure as i do not hear anything when it is idling. Could it be a misfiring issue cause by bad plugs or ignition coils?

If it helps, when I throttle the bike above 3k RPM the bikes somehow sounds like a V-engine? but when it gets in the upper RPM band it sounds alright.

Any inputs on this or experience with this you guys had?

@leontan505 , for my sanity would you please tape a mic closer to the bottom end of the engine. I hear a faint low-tone closer to the end of the video. I hope that its nothing and I'm just hearing things.

Even better if you can take a video whilst using something like this (Amazon.com
I've seen a similar tool in action and it impressed me, never used it my self however.

EDIT: Perhaps get a buddy to assist and use a rear paddock stand facing a wall to make life easier?

 

[leontan505]

@leontan505 , for my sanity would you please tape a mic closer to the bottom end of the engine. I hear a faint low-tone closer to the end of the video. I hope that its nothing and I'm just hearing things.

Even better if you can take a video whilst using something like this (Amazon.com
I've seen a similar tool in action and it impressed me, never used it my self however.

EDIT: Perhaps get a buddy to assist and use a rear paddock stand facing a wall to make life easier?

Have left the bike with my mechanic to do a full check =D Will be back stronger when it is done

 

[leontan505]

I have left the bike with my mehanic to do a full check and to replace what's need to be replaced. The previous owner owned the bike for 9 years but have not ridden it much! So for a peace of mind i am gonna do everything I can, except the engine parts if it is not required such as piston n rods....

To do list are as follows:
1) Valve clearance check
2) Throttlebody service and sync
3) Clutch basket and plates (Noisy rattling and knocking sound when I rev the bike)
4) New discs front and rear
5) New Servo Buddy (Error code 35 - 3 long and 5 short blinks)
6) Oil sight glass leakage
7) Compression check
8) Ignition Coils check
9) Fuel pump regulator and fuel filter replacement
10) Timing chain, tensioner and guides

Will keep you guys updated on the progess =)

 

[leontan505]

Throttle body set at factory.

If your mechanic can rebalance, please let us forum members know how?

Thanks!

Regarding the balancing of throttlebodies he uses a digital device similar to the mecury or guages ones used to balance carburators. Basically plugging the 4 hoses into the vaccum port (not sure if is it called that), then he would start the bike and rev it to see each of the 4 cyclinders vaccum level as per the digital meter. He would then take screwdriver to turn a particular screws on each cylinder's throttlebody, rev once and check the levels again. He does it across all 4 cylinders until the digital graph on the meters is levelled for all 4 cylinders.

 

[dannoxyz]

manometer to balance throttle bodies.

 

[NewRedRider]

Everything looks fine to me except replacing a CCT that may not be a problem. If it's not a problem why replace it. I think too many people got far too caught up in replacing perfectly good OEM parts out of fear. They would use a heavy weight oil that took longer to reach the CCT and instead of just blipping the throttle to increase the oil pressure they wrongly concluded they had a bad CCT. There are legitimate reasons to replace a CCT. Just make sure before you go and make the swap.

How many miles are on this bike?