Strange noise engine or transmission

[Old Rider]

after riding with what i suspect beeing a to tight timingchan feeling uncomfortable it may snap i ordered a new D.I.D  timing chain.Today i started the work
I have measured the old chain by tying a thin line (flyfishing backing) around the chain while rotating the engine .Whayt i found was that the old chain is
25 millimeters longer that the new !.the timingchain adjuster is fully expanded. 25 millimeters still seems very long so i think the new chain is to short
any one measured timingchain stretch after replacing it?
The chain is did SCA 0412A SV  has anyone replaced chain and used that chain?

[aj52]

after riding with what i suspect beeing a to tight timingchan feeling uncomfortable it may snap i ordered a new D.I.D  timing chain.Today i started the work
I have measured the old chain by tying a thin line (flyfishing backing) around the chain while rotating the engine .Whayt i found was that the old chain is
25 millimeters longer that the new !.the timingchain adjuster is fully expanded. 25 millimeters still seems very long so i think the new chain is to short
any one measured timingchain stretch after replacing it?
The chain is did SCA 0412A SV  has anyone replaced chain and used that chain?

That number shows up as an Suzuki timing chain.

[oldktmdude]

   How many links is it? The correct number is 156. That amount of stretch is not unusual, I replaced one recently that was at least that much longer than a new one.
   Regards, Pete.

[RPM - Robert]

See reply #19. http://www.fjowners.com/index.php?topic=16008.msg164116#msg164116  I do not recall what the measurement was as it has been a few years but with over 100,000 miles. 25 mm (almost 1 inch) of stretch, seems like a lot.

[ribbert]

People fit endless cam chains in FJ's because the engine is usually pulled down for other work anyway and it's no more trouble. Yamaha supply them that way because that's how they fit them during production. I guess it's happened but I've never heard of an FJ being stripped for a cam chain replacement only. (mine currently has 260,000km on the original)

I would not split an engine just to replace the cam chain, there is nothing wrong with split chains. Engine companies often use parts during manufacture that are economical during production but impractical to replace in a fully assembled engine, hence split chains. Many bikes also leave the factory with an endless drive chain for the same reason.

I'm not endorsing your decision to replace the chain by making these comments, just saying you don't need to pull it down if you want to replace it.

I have fitted many split cam chains and just last year one of our members here did the same. While in the finishing stages of a very comprehensive engine build he discovered the chain that had been supplied (and was now installed) was the wrong length.

Whichever way you do it, don't worry if the chain drops into the crankcase, contrary to the advice in the manual.

IMO

Noel

[racerrad8]

The timing chain is not usually the source of the noise as the tensioner keeps the chain taught.

The noise is usually the starter chain slapping around in there since it has no tensioners.

Randy - RPM

[Old Rider]

Thanks riders for helpful tips .But stubborn and often silly as i am i wanted to do this job my way and do a experiment
so here is a little uppdate:
Yesterday i started the job replacing my cam chain.I wanted to see if i could do it by splitting
the old chain temporary rivet the new on and rotating the engine  without even removing the
camchafts.I was thinking that it would be faster than removing the camchafts and the possibility
that i might snap a capbolt or muchroom some capbolt threads.look at it as a experiment 
I was wondering how i could make it and came up with the idea using zipties to keep the chain down
on the sprocket thoots.In teory it should work ,but i reality it was quite a fiddely job.
so first i started at the inntake sprocket upper right zipping the oldchain and split it then i
connected the new cain to the old and started the process rotating the engine a little and
adding more zipties and remowing zipties as i was rotating  .I found out that this was a very slow process and also
difficult as the chain was thight and easyly can slip a thooth.Everything was going sort of nice (and slow)
until i almost had the hole chain running thru the engine and about 10 centimeters left, then i
was a little out of focus and the chain slipped a thooth. :dash1:I could not get it back where it shold
have been so i just kept turning the engine carefully and watchin the valves hoping nothing was
colliding with the pistons.at the end i had the hole chain thru ,but then i could not put in the
masterlink in because of the chain had slipped a thooth.
so far so good but then i did a really silly thing  i removed the camchain tensioner thinking that if i
could get   slack on the chain i could get it one thooth back so i
could fit the masterlink.it worked and then i mounted and riveted the masterlink with my supersheep
super low quality ebay chain rivet tool.
But then i accedently rotated the engine with my foot clockwise
because i was stumbling and the wrench still sitting on the crank  .i was working in my
garage (wich is  very narrow dark and with deep gravel og ground)
.i then knew i for sure it was out of timing
then i tryed to rotate it back and realize that the chain was slipping on the cranksprocket bacause it was
so loose after remowing the cct.so then i definitly knew i was fuc... and out of timing
that is what i managed to do last evening .Im waiting to recieve the new camchaintenioner from the
dealer today.Now im just hoping that i dont do anything wrong when trying to get the timing right
again.i know i mayby can fu...up by not having the engine at real TDC i mean at the compression
stroke any tip about that would be very nice!.I know that i can feel when the compression stroke
is by holding my finger innside the plughole well not innside but at top of it im planning to
try to take the chain of the exhaust sprocket and rotate the camchaft a little without bending a
valve.any suggestions wold be helpful.
I took some pictures how my expremential ziptie method works il post later.I dont recomend the
metod and nex time i remove the camchafts instead.=)

[ribbert]

Thanks riders for helpful tips .But stubborn and often silly as i am i wanted to do this job my way and do a experiment

Why not just remove the tensioner, cut the old chain off, feed the new one through, join it, time it, job done.

Old Rider, I don't know if you are winding us up or not, but right from the onset you have wanted this to be the cam chain, despite no supporting evidence to that effect and you appear to have taken not one skerrick of notice of the opinions you asked for.

You have a manual, I'm sure it describes the cam timing procedure in detail.

Lots of folks here only too happy to advise, but if all you want to do is experiment with your own motor, fine, but if you want it fixed and want help in doing so, heed the advice offered.

Noel

[Old Rider]

First i want to clarify that the noise i got from engine was indeed the cam chain beeing very slack/stetched and when rolling on and off throttle i slow speed
it did make a strange noise i also had a backfire.
I know for sure it was the cam chain or infact the tensioner binding up and the spring not working. I know it because when i first opened the engine the 3th of june i could se the chain had a big slack i could push it down 4 centimeters between the camsprockets. When i temporary fixed it by losening the cct a little an tapping it i heard and felt the spring innside activated and the chain was thight again.
The chain was then stretched so it dident engage on the theeth on the camsprockets like riding on top of the sprockets even if it was very tight.
afterwards i rode the bike for some days and the bad sound from egine was completely gone. so yes it was the cam chain that made the noise.
Firstly i tought the noise was comming from the countershaft outer bearing because i also had a lose front sprocket.i fixed that with a new chain and sprocket set  ,but the nois was still there.I then tok the bike to the yamaha dealer 10 minutes ride from where i live and spoke with the the chief at the shop who has ages of experiens wrenching on yamaha bikes.He sat on the bike looking like a doctor listened to the engine and then tok it for a ride without a helmet .when he came back he listened a little more and then he sayd: You can forget the contershaftbearing it is not that it is your camchain tensioner.replace that and se what happens.
At first i was thinking he was wrong and that a cam chain rattle sounds more consistent and different, but as i wrote earlier he was infact right.
I have changed te cam chain now because i had a feeling it was too thight and might snap after working on the bike the 3th of june.
about the procedure of it was possible to change it with splitting it and run it thru i got no answer only that i had to tear down hole engine.At the moment
it is the middle of ridingseason here in Norway and i was planning on a 1700 kilometer trip op north so that was not an option right now but in the winter i might tear and rebuild the engine.One reason why i did it with zipties was i tought it was faster and also dident risk snapping a capbolt or damage any treads .The ziptie method i used works but it is probably faster taking the camchafts off so no i know that.
i have just now been out in the garage and reset the timing and everything seems fine just waiting for the new cct from the dealer hopfully it comes tomorrow.

[Old Rider]

a little uppdate i now measured the old chain and when laying it on the floor beside the flyfishing backingline i measured it when it was innside  the engine it is almost same lenght only about 2 millimeter shorter than the line so that means that the old chain is infact 23millimeters stretched!!.also when holding it with my hands
i can feel a stretcing motion when pulling at the ends another thing, the new chain lays perfect on the camsprockets opposite to the old who was riding high on sprockets.

[FJmonkey]

You mean like elastic?   

[RPM - Robert]

You should confirm what cam chain tensioner number he ordered. If he ordered the newer 4kg number you will need to replace the tensioner bolt as well as the old bolts are too short and you will struggle to get it started in the deeper threads of the new tensioner. If he ordered the 99999 part number one you will be ok. 4KG Tensioner was used on the 1995 and later models.

[Old Rider]

Fjmonkey yes  a little like a rubber band

Robert thanks for telling me that i will fore sure check that.One thing i found was the tensionerbolts sitting in now is different lenghts but else looking the same i dont know if thats normal one is about 5millimeters longer also the previus owner has tightened the bolts to much and done some damage to the threads the first couple of turns. i have a thredset tool and thinking of refreshing the threads or use some blue threadlock on them.
On the old tenioner the capbolt was thightened so hard i had to place it in a wice and use full force to get it lose the torque should be 6Nm !  im not going to reuse that but wanted to take a look at the springs.

[RPM - Robert]

I am talking about the Center Bolt The allen head bolts don't really matter as long as they are not too long as to bottom out and not seal and not too short so they pull the threads when tightened. Could be a language barrier but it sounds like you are talking about the two that hold the tensioner to the barrel assembly.

[Old Rider]

okay i see thanks for informing me i will check that when i hopfully get it tomorow .When i order it i gave them the number from the 86 parts catalogue so hoping i get what i need.