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2002 FJR1300 Clunk at idle

15K views 67 replies 15 participants last post by  passx 
#1 ·
Hi All,
Please help, 2002 with 52k emits knock noise at idle. More pronounced as it warms up. Bike runs great from 2000 rpms and above. No issues at higher speed. Has anyone heard a similar noise please?

Video: https://photos.app.goo.gl/iu18bh3J6iyRfZwQ9

Have tested TPS - fine
Have inspected plugs - fine

Does not sound like CCT, have listened to various videos.

Help......

Cheers,
Dave
 
#2 ·
Ouch, not a good sound. Is it my imagination, or did the idle drop when I heard the sound two or three quick times in a row? Hopefully, someone will come along soon with good ideas. I would not ride it until this is sorted out,but I guess you figured that out. Good luck
 
#3 ·
I agree. Sounds like a chipped gear piece floating around in the transmission, or something like that. The fact that it pulls the RPM's down a bit leads me to believe it is binding with the mechanical rotation of the motor or gearbox. Does it happen with the clutch pulled in? Unfortunately I think you are going to have to take stuff apart to figure out what this is. Good luck.
 
#5 ·
Hi Everyone,

Thanks for the replies so far. CCT is being ordered today, plus new plugs. Will also get some rubber caps to remove the PAIR system. The bike runs great (other than the sound in Video) and I had it out without issue for 160km test run last Saturday. Once again above 2000rpms the problem does not exist.

Pulling the clutch in does not help the noise. The noise is far more subtle at initial start, gets louder as it warms up and hits lower idle speed. If you hold the revs at 2000 then it will not make the sound. CCT for me. (Fingers crossed this is all)

There is a gent in Melbourne Australia that listened to my video and says he had the exact same symptoms. CCT resolved it. Will go with this for next troubleshooting step.

Cheers,
Dave
 
#6 ·
The noise may be the cam chain catching on the tensionerbars occasionally. If that does not have the latest CCT, then change it ASAP. If you like, remove the right engine cover and see if you have slack in the cam chain, if so, a sure indication of CCT not having tension. I'd recommend you don't even run the engine, risk of skipping teeth and doing expensive damage.
 
#11 · (Edited)
The sound comes from the injectors..It isn't a mechanical sound.If you watching the needle in the gauge you will notice the fluctuation when you hear that noise.Perhaps a bad fuel or a clogged injector or something around there...Also a defective TPS can cause this symptom at idle.On the test this thing seems that it works fine but it doesn't works right..This sound has nothing to do with the CCT.
 
#12 ·
Thanks to everyone for your contributions. As mentioned I will start with CCT and plugs, plus pair removal while I am at it.

I hope to have a much better sounding video to post as a result.

Fingers crossed.

Great forum, great info.

Cheers,
Dave
 
#14 ·
It may be that there is no slack noticable, a good sign. Agree change the CCT anyway since it has no dots (old original design). Be sure to ty-wrap the chain at the crankshaft end to prevent the chain from drooping down off the crank sprocket while you have no tension on the CCT when you release it. Also agree that the strange noise may be coming from elsewhere, but let's eliminate the CCT first.
 
#15 ·
Thanks Mate,

I feel better already knowing that the chain gear and timing seem to be in order. The manual says: \

Make sure that the timing chain tensioner
rod comes out of the timing chain tensioner
housing smoothly. If there is rough move-
ment, replace the timing chain tensioner.

So I may have a problem yet with the CCT that I just cant detect when it is under load. I guess I will see when I get it out.

In the back of my mind I am wondering if the clutch might need inspection. I saw a video of a guy yesterday taking the plates out and bathing them in oil then re-installing cause they were dry. What is this meant to improve in your opinion?

Regards,
Dave
 
#16 ·
The original CCT has a weak spring that got weaker with age. It may be smooth......


The clutch soak is meant to a) you'll clean the plates while you're in there, b) coat them with oil so the clutch releases smoothly, less drag when cold. The clutch does not get much oil normally. Do it once, should be good. It's optional, and usually only done if you're having clutch drag and associated shifting issues.
 
#17 ·
Before you take anything more off the bike I have a idea to help find the place the noise is coming from, do you have a long shanked screw driver in your kit, start the engine ,put the handle against your ear and the working end on different places on the engine until you find where the noise is loudest, then you can diagnose the problem better
 
#19 ·
Hi Everyone,

So an update. Pair system removed and capped, new plugs with gaps checked, New CCT installed. NOISE IS STILL THERE as per original video.

When placing a screwdriver on the right hand side of engine and to my ear in various places, it sounds like clutch noise to me as the noise is loudest on the clutch housing cover. Any ideas what I am looking for that would make this kind of noise?

Cheers,
Dave
 
#23 ·
Not sure if it's clutch related, but it's easy enough to remove the clutch cover and check if the clutch plate "keys" have worn grooves in the clutch basket, for example. You can completely remove the clutch plates and have it all back together in about an hour or so.... which might not be a bad idea to inspect all the plates individually. Looking at it would confirm or deny it as a cause of the noise.
 
#25 ·
Nobody has yet mentioned the backlash adjustment on the two balance gears to the crankshaft. I know I keep harping on about my old Hayabusa, but, similar four cylinder engine, similar build, similar capacity, and mine starting making odd clattering noises at a low mileage caused by loose mesh in the balance gears. You need the manual to show you how to do this really, you can do it with the engine running, too tight they will whine, too loose and they will make a horrible odd- sounding clattering noise.
The Hayabusa has one balance shaft, the FJR has two - look at the parts diagram.
 
#27 · (Edited)
As I posted - the balance shafts are not chain driven, they are driven at 2 x crankshaft speed by a gear on the crankshaft, it's not chain tension, it's gear mesh.
They are inside the crankcase on the left-hand side of the motor, so the adjusters are also on the LHS.

Edit - I just looked at a better, clearer parts diagram, the front shaft adjuster is on the left and the the rear adjuster is on the right - apologies, I don't like dishing out wrong info!

From the Haynes manual, the adjustment is as follows:-

Static adjustment with cold motor.
Slacken the adjuster pinch bolt. Turn the adjuster shaft slightly clockwise using a flat bladed screwdriver until a torque of 0.4 Nm is reached (meaning resistance is reached because the gears are now meshed tight together) then turn the shaft one graduation anticlockwise marked on the holder when adjusting the front balancer shaft and two graduations when doing the rear.

Then carry out the dynamic adjustment.
Must be carried out with the motor hot.
Let the motor idle.
Slacken each balancer pinch bolt in turn and turn the shaft slightly one way and the other to find the point where the gears run at their quietest, too tight and they will whine, too loose and they will clatter.
(Resist the temptation to have them meshed too tight to get rid of any slight gear clatter - my remark).
Tighten the pinch bolt after each adjustment.
Rev the motor to check noise above idle.
 
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