Knock Knock...
Here's an opportunity for some educated guesses. My engine has started knocking and I'd love to know what it is. Today the engine is coming out so I can hopefully get to the bottom of it and fix it.
I think it's a big end rattling away. Anyone got any other theories? I don't want to miss anything this time so your suggestions will be most appreciated.
http://www.youtube.com/watch?v=2I9AA...layer_embedded
I think it's a big end rattling away. Anyone got any other theories? I don't want to miss anything this time so your suggestions will be most appreciated.
http://www.youtube.com/watch?v=2I9AA...layer_embedded
Last edited by CBRclassic; Mar 28, 2010 at 05:21 AM.
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Wow ...not good Henry ...
I listened to it a few times and to be honest , om not sure what it is ...
Was she making the noise from the start after you re built her ?
If not ...I have my doubts as to whether she would would run a bearing shortly afterwards for no apparent reason ?
It could be any number of things mate ... sorry om not much help
I think I would be checking the chains down below first ... check oil for any shrapnel .... drop the sump perhaps to see if anything has gone astray inside ...primary tensioner ?
anyway ..not good Henry
I gotta sleep now ..ol be thinking of her ... racking my brain ..
I listened to it a few times and to be honest , om not sure what it is ...
Was she making the noise from the start after you re built her ?
If not ...I have my doubts as to whether she would would run a bearing shortly afterwards for no apparent reason ?
It could be any number of things mate ... sorry om not much help
I think I would be checking the chains down below first ... check oil for any shrapnel .... drop the sump perhaps to see if anything has gone astray inside ...primary tensioner ?
anyway ..not good Henry
I gotta sleep now ..ol be thinking of her ... racking my brain ..
Ummm think you are not far off there Steve sounds like tensioner / chain related alright
kinda sounds like my cct on a cold morning, like you say Henry might find pieces of it after pulling the sump....
I 'd second Steve's guess too.
kinda sounds like my cct on a cold morning, like you say Henry might find pieces of it after pulling the sump....
I 'd second Steve's guess too.
Thanks for your starters but I"m not sure it's chain related as the knock is definitely a knock rather than a constant whoosh or rattle which I would expect from a chain problem.
TO answer your question Steve, when she first went back togather there were no noises and all seemed sweet. About 1000 miles later I noticed what seemed to be a loose tappet noise, very faint. I check the tapets and found a cople of them a bit on the tight side but only about 0.01 mm so not like it was really bad.
This noise suddenly got much worse after a good thrash one day when I really pushed the speed up, only for a couple of minutes but when I slowed down again I could hear it straight away.
Anyway, the engine is on its downward journey so I should hopefully be able to find out tomorrow.
Only problem is I'm off on holiday for a week starting Tuesday so time is not on my side. We're driving down to Barcelona and to be honest I'd much rather be away than working on the bike.
Thanks for your input Sprock, all opinions gratefully welcome.
TO answer your question Steve, when she first went back togather there were no noises and all seemed sweet. About 1000 miles later I noticed what seemed to be a loose tappet noise, very faint. I check the tapets and found a cople of them a bit on the tight side but only about 0.01 mm so not like it was really bad.
This noise suddenly got much worse after a good thrash one day when I really pushed the speed up, only for a couple of minutes but when I slowed down again I could hear it straight away.
Anyway, the engine is on its downward journey so I should hopefully be able to find out tomorrow.
Only problem is I'm off on holiday for a week starting Tuesday so time is not on my side. We're driving down to Barcelona and to be honest I'd much rather be away than working on the bike.
Thanks for your input Sprock, all opinions gratefully welcome.
I think I've found the culprit.
After taking out the big end shells and checking them thoroughly I have discovered that some king sized numb skull has fitted the wrong shells to No. 1 con rod.
The bearing surfaces of all of them showed varying amounts of wear none catastrophic in my opinion but the outside surfaces of the shells on #1 were showing signs of wear??????? WTF??????
No. 2 was in a similar state but not quite so discoloured. It was from this side of the engine that the tapping was coming from so I felt I was at least on the f=right track after finding the wear.
I taped each set of shells together and labeled them for reference later.
There is a code number on each Con rod and a code on the end of the crank shaft. These indicate the relative diameters which can then be cross referenced to the manual to tell you which set of shells should be fitted.
My Con rods consisted of three 1's and a 2. The Crankshaft codes were all B.
This meant I should have had three pairs of green shells and a brown but I had all greens.
That means that No. 1 was suffering an additional clearance of about .020 as opposed to .009. That's taking the average tolerances given.
While this may have worked for a while, indeed a fairly long period it seems that it has finally showed up and made its self heard. Damn it, why me?
Actually the whole operation this time was painless. It's taken no more than 5 hours of work from turning the engine off to opening up the crank case and fetching the shells out. There's something to be said for having done it recently.
I couldn't find anything else awry. All looks good in there.
I haven't even taken the head off or the camshafts.
Well, I'll report back as soon as the shells arrive and let you know if this cures the problem. Cost? About £100.00 inc VAT. Sigh.....
After taking out the big end shells and checking them thoroughly I have discovered that some king sized numb skull has fitted the wrong shells to No. 1 con rod.
The bearing surfaces of all of them showed varying amounts of wear none catastrophic in my opinion but the outside surfaces of the shells on #1 were showing signs of wear??????? WTF??????
No. 2 was in a similar state but not quite so discoloured. It was from this side of the engine that the tapping was coming from so I felt I was at least on the f=right track after finding the wear.
I taped each set of shells together and labeled them for reference later.
There is a code number on each Con rod and a code on the end of the crank shaft. These indicate the relative diameters which can then be cross referenced to the manual to tell you which set of shells should be fitted.
My Con rods consisted of three 1's and a 2. The Crankshaft codes were all B.
This meant I should have had three pairs of green shells and a brown but I had all greens.
That means that No. 1 was suffering an additional clearance of about .020 as opposed to .009. That's taking the average tolerances given.
While this may have worked for a while, indeed a fairly long period it seems that it has finally showed up and made its self heard. Damn it, why me?
Actually the whole operation this time was painless. It's taken no more than 5 hours of work from turning the engine off to opening up the crank case and fetching the shells out. There's something to be said for having done it recently.
I couldn't find anything else awry. All looks good in there.
I haven't even taken the head off or the camshafts.
Well, I'll report back as soon as the shells arrive and let you know if this cures the problem. Cost? About £100.00 inc VAT. Sigh.....
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The bearing surfaces of all of them showed varying amounts of wear none catastrophic in my opinion but the outside surfaces of the shells on #1 were showing signs of wear??????? WTF??????
yu may have been getting a bit of shell chatter ...? that's all that will cause the outer surfaces to wear, but the clearances must be a fair way out to allow that to happen ...
Since you left the head on ...may I ask if the upper shells were easy to get out with the crank still in ...?
and no, I have never gone my lower bearings on my CBR ...lol
Wow, Henry, it's getting to a point where you could tear down a motor with your eyes
closed, on one foot and an arm tied behind your back in a vat of burning oil
That's something you get my
vote for the week
Waay out of my league .
Amazing how Steve & I came so close to getting it right , lol , eh Steve ?
closed, on one foot and an arm tied behind your back in a vat of burning oil
That's something you get my

Waay out of my league .
Amazing how Steve & I came so close to getting it right , lol , eh Steve ?
Last edited by Sprock; Mar 29, 2010 at 04:02 PM.
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Wow, Henry, it's getting to a point where you could tear down a motor with your eyes
closed, on one foot and an arm tied behind your back in a vat of burning oil
That's something you get my
vote for the week
Waay out of my league .
Amazing how Steve & I came so close to getting it right , lol , eh Steve ?
closed, on one foot and an arm tied behind your back in a vat of burning oil
That's something you get my

Waay out of my league .
Amazing how Steve & I came so close to getting it right , lol , eh Steve ?
I have known people to go rip big end bearings out for replacement and then whack them back together and still have the phantom noise
and these 1000F engines can make some weird freakin noises when chit goes west mate .... we shall see , but for Henry's sake I do hope he has it by the throat ...
Wow, Henry, it's getting to a point where you could tear down a motor with your eyes
closed, on one foot and an arm tied behind your back in a vat of burning oil
That's something you get my
vote for the week
Waay out of my league .
Amazing how Steve & I came so close to getting it right , lol , eh Steve ?
closed, on one foot and an arm tied behind your back in a vat of burning oil
That's something you get my

Waay out of my league .
Amazing how Steve & I came so close to getting it right , lol , eh Steve ?
Yeah...... ahem..... you were both really close with your chain theory's. I'll have to tell you that the venerable Trout PM'd me and thought you were both on heavy drugs. He also thought the whole thing was a figment of my imagination. Now I just don't know any more.
Glad I'm off on holiday tomorrow. A long drive to Spain should sort my shattered mind body and soul, though Sarah will be a bit pissed off when she realises I'm doing the whole thing blindfolded, handcuffed to the door handle with a plastic bag over my head.
See you all in a week...... Yeeeeeeeeeeeha!
By the way, any of you done a compression test lately? I need some figures from you all for comparison. Mine were all within 25PSI of each other but I need some Forum data.......
Loves ya's all!


