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Strange noise engine or transmission

Started by Old Rider, May 30, 2018, 02:09:17 PM

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Old Rider

So lately i have notised a sharp metal tick/rattle sound its hard to explain the sound but its like high voltage short sparking sound lasting only a cople of seconds at time.
It is mostly right when i roll on or cut the trhottle in first and second gear at lower speeds .But also sometimes when ridig at more speed also think that it
comes in small roadbumps .
First i checked the front sprocket it looked fine no visual wornmarks but  it had gone totally loose.Its a jt sprocket.I then retorqued the sprocket to 85NM
and ordered a new sprocet chainset.Yesterday i changed the sprockets and chain and the old one had come loose again and bent the lockwasher open and losened the nut.I put a new lockervasher and retorqed to 90Nm.one thing i notised was that the new sprocket also had a loose fit on the splines exatly as the old (also jt sprocket.)The splines on shaft look good.
after a ride the bad engine noises came back ands seems to get worse when engine gets hot.I took the bike to the yamaha dealer and skilled a meckanic
tested the bike for a little ride.I told him i tought mayby it was the bearing sitting behind the sprocket ,but he sayd that he think its the camcaintensioner or worn out camchain. but i had stretched camchain before on my fj600 and it sounded more like a constant rattling.I dont like riding with this thinking that bad things can happend like a blocked rearwheel .... id had blocked rear wheel before but then it was a bad 2 gear on a fj1100.
so what do you think is this a total rebuild?
i was thinking og first take the camchaintensioner and loosen the bolts a cople of turns to see if it clicks out one click and then retighten the bolts .
if i find the camchain is stretched im going to try to change it by cutting it and splice in a new one is that doable on the fj? :wacko2:

Urban_Legend

These bikes are known to have a rattle when taking off from a stop and at low revs. this is usually caused by the starter chain, not the cam chain. It is very common and of no immediate concern.

Not sure of the fix (other than splitting the cases and installing a new one) and most of the bikes i know that have this issue (and that most of them) have been this way for years.

Mark
Mark
My Baby (Sparkles)
84 FJ1100/1200 motor
92 FJ 1200 - Project bike. Finished and sold.
84 FJ1100 - Project bike.

Pat Conlon

1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

Urban_Legend

Here is a phota of the inside of my motor (89 Fj1200) looking from the bottom with the two chains ( starter and Cam) labelled and this bit I just fixed. Hope it helps you. This motor has about 30k km ( 18k miles) the starter chain was a loose fit.

Mark
Mark
My Baby (Sparkles)
84 FJ1100/1200 motor
92 FJ 1200 - Project bike. Finished and sold.
84 FJ1100 - Project bike.

Old Rider

thanks for reply .I forgot to mention that i know about the starterchain rattle and have had that to it sounds more like a chain jumping over sprockets just as i takeoff in first .When i think about it i havent had that starterchain noise lately so mayby the starterchain noise has turned into the sound im hearing now.The starterchain is for sure stretched the bike has run 120 000 kilometers its a 86 fj1200.What worries me is that i can feel somtings not right ive ridden fj for about 15 years and usally i igjore all the noises from the engine.I feel like a roughness in the transmission.That and that my front sprocket nut is starting  coming loose i dont like. When i changed the sprocket i tryed to see if there was any play in the outputshaft but it felt totally stable and also very
easy to turn with fingers.The output shaft for the gearselector had play in it but no leaks around the seals for outputshaft or gearselector shaft

oldktmdude

   If you are concerned enough, drop the oil out of it and see how it looks. Any excessive metal flakes or "chunks" will confirm that you have a problem.
If you don't find anything out of the ordinary, keep riding and push the ear plugs in deeper.   :good2:
Regards, Pete.
1985 FJ1100 x2 (1 sold)
2009 TDM 900
1980 Kawasaki Z1R Mk11 (sold and still regretting it)
1979 Kawasaki Z650 (sold)
1985 Suzuki GSXR 400 x2 (next project)
2001 KTM 520 exc (sold)
2004 GasGas Ec300
1981 Honda CB 900 F (sold)
1989 Kawasaki GPX 600 Adventure

ribbert

Noises can travel, they can be amplified and the pitch distorted (and change over the net). I listened to that clip about a dozen times and have no suggestion other than to say it has some resonance, depth and oiliness about it, something I would normally associate with being in, or on, the gearbox.
A good tool for finding noises is your fingers, as you are spinning it, touch the areas around where you think the sound is coming from and see if you can feel anything consistant with the noise. Even better, put a large screw driver on the area with your ear pressed onto the handle and move it around to different locations. I still find that works better than my automotive stethoscopes.
Have you checked the carrier bearing in the rear sprocket? Not that it particularly sounds like it, but just eliminating possible causes, they seem to behave differently to wheel bearings when shot.

Forget about the cam chain, the motor isn't running in the video.

Back in the 70's I had a bloke bring me a yank tank with a massive V8, he had just had a top to bottom overhaul, crankshaft grind, re-bore, new pistons, heads etc. after it developed a knock. He had opted for a full rebuild because reliability was paramount, he towed horses all over the country with it.
The trouble was, it still had exactly the same knock after the rebuild! After a few minutes of looking, listening and feeling I pulled the PCV valve out of the rocker cover, the surprisingly deep knock suddenly became a light click, click, click.... in my hand. I pushed it back in and the clicking turned to knocking again. A broken spring in the PCV valve, at the time a new valve cost about $2. I can still remember the look on his face, it was near distorted with rage.

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

red

Quote from: oldktmdude on May 31, 2018, 06:41:01 PMIf you are concerned enough, drop the oil out of it and see how it looks. Any excessive metal flakes or "chunks" will confirm that you have a problem. Regards, Pete.
Old Rider,

On the same idea, you can get a magnetic oil drain plug, and/or a ring magnet for the oil filter,  from RPM.  Magnets are better than any oil filter; they can catch and hold atoms of iron or steel.  Lacking either one, you can attach one or more strong magnet(s) along the bottom side of the oil filter; just keep the magnet(s) in place until the oil filter has been removed from the engine.
Cheers,
Red

P.S. Life is too short, and health is too valuable, to ride on cheap parade-duty tires.

Old Rider

Thanks for your input guys here is an uppdate.
Last sunday i desided too open the valvecover and check the cam chain and see if it was lose and
also pull out the carbs and check the cam tensioner.Alos desided i should fix the frontsprocket
nut with locktite threadlock.I use to stand outside on a deserted parkinglot when i work on the
bike and i wasent too keen on doing this in the heat as i have heartproblems i had 3 heartattacs 
before and i get really exhausted working on the bike for long times in heat and its been
extremely hot weather here in Norway this month tempratures raging between 26-32 degree celsius
hottest may meausered in over 100 years! .The longtime forecast sayd that the hot weather will continue so
my impatiense of getting this done got me =)
anyway what i found was at first with the engine on TDC the timingchain seemed to be fine and not
lose but a closer look from side the chain was riding high on the camsprockets as it dont fit down
on the sprocet thoths.The sprocket theets seems not worn no sign of the theeths getting pointed 
the timingmarks was a little out did not center in the holes in the camchaft caps.(mayby that is
why i had a little backfiring lately)
Then when i put a screwdriver on top of chain betveen the sprocets and pushed down it got very
loose.like 3-4 cm hanging down.
I then pulled the carbs to get to the camchain tensioner.i losened the 2 tensioner allenkey bolts
a little to see if i could get the tensioner spring to "click out" i did not hear any click so i
screwed the allenkey bolts a little bit further out mayby 3-4 millimeters.Then i felt something
happened and felt the resistanse from the spring inside tensioner pushing the tensioner outwards.i
could push the tensioner into the engine by hand so i desided the i did not need to take the
tensioner completely out to check it,because i was afraid that the chain might get so lose the chain
would jump over a thooth on the cranksprocket.I then screwed the allenkey screws back in and
thightened them to tourqe specs.
Then when checking the chainslack it seemed thight (too thight?)the timingmarks had now got centered in the camchaft capholes also the lines in marks on the sprokets aligned with the top surface of sylinderblock i took off the camchain guidance
between the sprocets to better see how thight the cain had got. when i grabbed the chain with my
fingers i could move it just 5-7 millimeters up and down in the middle between the sprockets.Is
that way to thight?? also i notised that the chain still dident seem to fit the theeth on the
sprockets like riding high on the sprockets. i know this is a sign of a  stretched chain on a
rearwheel drivechain but not sure how it is on a timingchain. I have not any good picktures from a
fj engine to compare with.so if you have one please post it.Anyway i turned egine a couple of
turns on the crank and it moved quite easy not too hard to turn it around.and no bad sounds.
I then decided to just put the the valvecover back on and carbs back in and start the engine and
listen to it.When finished i fired her up and i could right away hear a different sound from
engine much quieter and almost like a sewingmachine.I rode her a little and the bad tick/scraping
sound was totally gone i tryed to see if i could make the sound come back by driving slow in first
and second gear slipping with the clutch then roll on /off with the trhottle and take off fast
riding over bumps ets ets also tryed to rev the egine up in a little higher speeds (as i heard
that if the camchain is too tight the engine will not rev up easy) and the throttleresponse seems
much quicker now there is no lag/hesitatin when turning on the throttle and also i got better
acceleration and on top of that no backfiring!!.The bad sound is totaly gone(crossing fingers!) and the engine sonuds
like new no bad noises! but there is a but a very BIG but...When i drive and listening to engine i
can hear that summing sewingmachine noise and it worries me that its mayby the sound of a too
thight camchain that will snap....

So here is my questions :
is it normal that the chain seems to be riding high on the camsprockets ? does anyone have a

picture from the sidewiev of the camchain laying down on the sprockets?

How tight is too tight ?i can mowe the chain about 5-7 millimeters up/down and it feels thight

and last if my chain is stretched too much im planning to change it by rivet it onto a new chain

and turn the crank to it gets around and then mount a masterlink is that possible?

anyone had a too tight camchain snapped?

fjbiker84

This may show the cam chain as it rides over the sprockets in a way that will help you.  Shortly after this photo was taken I decided to replace the cam chain tensioner with a new RPM tensioner.  In my case the PO had installed a manually adjustable tensioner and I was concerned that the tension wasn't correct.   

red

Old Rider,

If your Cam Chain was loose until you started fiddlin' with things there, you DEFINITELY need a new Cam Chain Tensioner.  That old one is binding or something, and if it fails, you can destroy the whole engine in a heartbeat.  I would strongly advise NOT running or riding the bike, until you get the new CCT in the engine.

There are right and wrong ways to do that CCT change, so it will be worth searching here for a tech post about how to.  This is not a job for wingin' it.

You will not need to be concerned about Cam Chain tension with a new CCT; the tension will be correct.

For the kilometers traveled, I would doubt that your Cam Chain has stretched significantly.  These are long-winded engines, and yours is still fairly young (at the odometer), as FJs go.
Cheers,
Red

P.S. Life is too short, and health is too valuable, to ride on cheap parade-duty tires.

Old Rider

Fjbiker84 Thanks for posting the picture .Idiot as i was i forgot to take some pictures of mine to compare but as i remember it looks like my camchain is riding a little higher on the sprockets than on the picture.before i losened the cct i the chain looked like on the picture but when pressed on the top i could press down  the chain about 3- 4 centimeters and after i repositioned the tensioner the slack is only 5-7 millimeters.
red : you are right about the tensioner might have been binding i first planned to take it completely out and se if i could sevice it but when i started screwing the 2 allenkey bolts out a little at time on each side i suddenly felt that it extracted the rod innside.The spring innside started to work again.at that moment the cct was about 3-4 millimeters out from engine and i could easy push it towards the engine with my hand.I then desided to just screw it back in and did not use any force to bolt it back. But when feeling on the chain at the middle of the camsprockets it felt tight i can move it about 5-7 millimeters up and down.dont know if that is too tight.

RPM - Robert

Did you remove the spring assembly before removing the allen screws holding the tensioner in? If not you need to remove the springs and the entire tensioner and reset the tensioner all the way in. (Or replace with a new one) After resetting the tensioner do not put the spring back in it until you have it bolted back up to the motor. If you leave the spring in and unbolt the tensioner it will automatically extend which can cause too much tension on the cam chain. You should also replace the tensioner gasket while it is off. No need to take everything back apart for an oil leak that could have easily been prevented.

Old Rider

Hi RPM Robert no i did not unbolt the springcapbolt at the backside because it was very tight not possible to losen without destroying something was a little afraid i might snap the bolts holding the cct inplace. so i screwed the hole tensionerassembly out mayby 3 millimeters and then i felt the spring activated .
I had some gasket material sheet with me planning to make a new gasket but i could not see any rip in the old one so i tok the chance it was okay .I have not had any leaks yet i rode the bike alot yesterday.The reason i did not remove the tensioner completly is that i was thinking that the chain was so stretched that when i remove the cct form engine the chain would jump over a thooth on the cranksprocket.The question now is is my chain too tight or is it also stretched .Im going to replace the atleast the cct an also the chain i think just wondering if i can manage to change it without splitting the engine.

RPM - Robert

If you did not remove the center bolt and you heard the click, you have now hyper-extended the tensioner. You need to loosen the center bolt and then reset the tensioner. They are tight, but have never had an issue breaking the mounting bolts to remove it. If needed you can use an pneumatic impact gun to break it free.

Once you have the tensioner removed, you need to fully compress the plunger and the re-install. The install the spring and center bolt to ensure the tension is correct.

The way it is now is going to cause excessive stretch to the chain and cause the rubber chain guide to wear through the rubber at an accelerated rate.

No the timing chain can not be replaced with out splitting the case with the Yamaha timing chain. At one point I believe someone offered a split timing chain but we have never used one on the FJ.

When we build motors, it is better for us to take it apart and inspect everything than try and do a cheaper job and possibly cost more later on items that could have been easily checked and replaced while doing the work the first time.