Not again!! Cam Chain Tensioner Spring

[sirgalahad3]

Hmm. I am aware of the ratchet type adjuster and would be happy with that set up. As the fazer seems rely totally on a spring worries me. As years go on the spring will get no stronger I guess. I think I will probably change mine.
On another note: Is it possible to buy just the spring from Yamaha. If so it seems a good idea to change just the spring to me. That way you have the constant correct tension plus the security of a brand new spring. Maybe change spring every 10,000 or 5 years? Saying that I suppose the tensioner is only available whole?

[devilsyam]

[devilsyam]

This is a cam adjuster cock up engine had done 20k

[sirgalahad3]

Today my manual adjuster arrived. What a quality item it is. Very well made and finished. Fitted quite easily but there is an intermediate stage where it could be too tight or its in the right place. It can never be as accurate as the automatic one IMHO.
Anyway fitted and looks good.
Which brings me to the standard one. If you take it apart there is a very delicate spring in it which I can see could break quite easily. But, and here is the but.. This spring rotates clockwise and forward the plunger on a strong worm thread to take up any chain slack. It not the spring that takes any strain,its the worm thread. If the spring were to break it would certainly not be able to move forward to take up any more slack for sure,or be able to spin the plunger back. What I cannot see is how the plunger can jump back violently when it has to turn on the worm thread. Over time as its not under spring tension if it breaks I guess it could vibrate back slowly on the thread and make the chain rattle but this would not be catastrophic failure.
Anyway, manual here.

[pilgrim]

  I've had 2 cam chain tensioner springs let go on me, and when you take the bastard thing off and wind it out to its full extent, you can push the piston back in quite easily.
Believe me, when it goes, it goes. BOOOMMMMMMMMMMMMMM!
I am getting seriously irked with this whole thing now, so I am going to say my final word on it, and never speak of it again, Ever.
The Gen 1 Yamaha Fazer 1000 has a shitty little spring in the cam chain tensioner which, if it snaps, and this is a rare condition which might or might not happen to you, can fuck your engines top end in no time flat. Period. No warning rattles, no ratchets to hold all hell unleashed back, just gone.
Pop.
Take it apart and you can quite easily push the tensioner piston back in, I know this, I have done this. Your cam chain will do this in the blink of an eye, and laugh while it bends the shit out of your inlet valves   9 of them the first time
I will now be relying on a manual cam chain tensioner, and a sharp ear for rattles from that area of the engine.
And no stupid thinner-than-cheese-wire spring will hold my fate in its scrawny little coils again, the bast.
I'm off now, take it easy folks, and pray you're not as unlucky as me

[sirgalahad3]

Hi Pilgrim, thats certainly interesting. Upon taking mine apart I can only say its different to yours. The spring on mine only winds the plunger forward on a worm thread. If the spring were to break,which is certainly possible,the plunger doesnt go back, the worm thread wont allow it too.
My plunger will not push back in,even without the spring fitted. Seems a good design to me?
Anyway good debate at the very least!
In hindsight I would not have now gone manual but hey,it looks cool!

[Simon.Pieman]

My plunger will not push back in,even without the spring fitted. Seems a good design to me?
Anyway good debate at the very least!
In hindsight I would not have now gone manual but hey,it looks cool!

Have you got pictures? This might be a tensioner from another model/engine, or perhaps Yamaha modified the design of the original.

[Hedgetrimmer]

I've had 2 cam chain tensioner springs let go on me, and when you take the bastard thing off and wind it out to its full extent, you can push the piston back in quite easily.
Believe me, when it goes, it goes. BOOOMMMMMMMMMMMMMM!
I am getting seriously irked with this whole thing now, so I am going to say my final word on it, and never speak of it again, Ever.
The Gen 1 Yamaha Fazer 1000 has a shitty little spring in the cam chain tensioner which, if it snaps, and this is a rare condition which might or might not happen to you, can fuck your engines top end in no time flat. Period. No warning rattles, no ratchets to hold all hell unleashed back, just gone.
Pop.
Take it apart and you can quite easily push the tensioner piston back in, I know this, I have done this. Your cam chain will do this in the blink of an eye, and laugh while it bends the shit out of your inlet valves   9 of them the first time
I will now be relying on a manual cam chain tensioner, and a sharp ear for rattles from that area of the engine.
And no stupid thinner-than-cheese-wire spring will hold my fate in its scrawny little coils again, the bast.
I'm off now, take it easy folks, and pray you're not as unlucky as me

You don't like it then...?

[solorider]

It has been the R1 tensioner is better, what is the main difference to the fazer one? Is it that the R1 unit has a ratchet type?

[Kosmic Kartman]

I had a manual cam chain tensioner arive in the post yesterday and I'll be fitting it later in time for LoFo blat out tomorrow.

[PieEater]

I have just had a look at my original tensioner (2001 FZS1000), it does indeed have some kind of mechanism to stop the tensioner from being pushed back. The only way I was able to retract the tensioner was to insert a small flat headed screwdriver in the unit and turn the small screw adjuster.


So what I assume is happening on the catastrophic failures is that first the spring fails then as the untensioned chain gets loose enough it starts slapping the tension blade and eventually the ratchet mechanism gives way under the constant pounding. This would potentially explain why Pilgrim is adamant that there is no ratchet mechanism because in both his tensioners it had given way some time after the spring gave up the ghost.

[Simon.Pieman]

This would potentially explain why Pilgrim is adamant that there is no ratchet mechanism because in both his tensioners it had given way some time after the spring gave up the ghost.

This is why I was scratching my head metaphorically, because if there was no ratchet system the plunger would simply go in and out from new and not do any tensioning. I didn't want to sound unsympathetic with pilgrim tho, I had a semi-auto tensioner go on a Z650 eons ago and it also made me very cross.

[sirgalahad3]

Ok pics of the tensioner fitted to my 03 bike.
1 Tensioner
2 Plunger with internal thread
3 Male worm thread
4 Exploded view
5 Torsional spring
The torsional spring is quite fine as you can see but this spring only applies a torsioal twist to the plunger which then moves forward on the thread if there is any slack to take up.  It  is not a push spring or anywhere near strong enough to apply enough pressure to the chain slipper.
If the spring is removed from the tensioner you cannot push the plunger back,as Pie says this can only be manually with a screwdriver.
Maybe later bikes have a different tensioer fitted to Pilgrims I dont know but this one looks fine to me.
Manual here now but will probably go back as I feel the auto one provides more progressive tension. I see more engines being wrecked by over tightening of manual version than tensioner failure of the original unit buy as Luke quite rightly says it everyones choice at the end of the day.

[sirgalahad3]

Pics

[sirgalahad3]

Pics

[sirgalahad3]

Pic

[solorider]

I have decided to go down the manual tensioner route, I bought this one off eBay  http://www.ebay.co.uk/itm/281160023278?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 and it certainly looks good and looks better than the other one I saw on eBay

[Simon.Pieman]

 I phoned Yamaha Technical Dept yesterday and asked them about camchain tensioners. They didn't really enlighten me on anything and what the technician had to say doesn't really further this thread. But here is a summary of their views on CCT failure.
The technician said that they do keep data on engine components that give problems, but failure of the CCT on the Fazer engine is so rare they don't have any record of such, he was aware that such things happen and you should consider your self very unlucky if it does happen, but it's not something to worry about he said. Apparently, in France some years ago there was a number of tensioners being replaced by dealers as a matter of course at 30,000 miles but it wasn't a directive by Yamaha. This rash of replacing the CCT might have been a result of rumour on forums he said and that it's always best to have engine problems discussed and investigated by a Yamaha mechanic.
 I told him that my own engine at 57,000 miles sounds mechanically noisier than it did say 10,000 miles ago and he said that it could be a number of things but with regards to the camchain and tensioner it might be that the chain is worn rather than the tensioner not working.
I said that I basically can't be arsed to take the engine down to have a look at the chain so would it be worth replacing the tensioner? He replied that in my case 'it wouldn't hurt' and that if the chain quietened down then all well and good, 'but I'm not saying that your tensioner is probably worn out'. So, non commital to admitting any endemic problems with the CCT.
He went on to say that 57,000 miles is considered a high mileage for a motorcycle engine and that if you took such a motor apart for some reason then you should certainly replace the camchain on reassembly, not because it's totally worn out, but because it's probably more than halfway to significant wear.
 As for manual tensioners, he said he wouldn't comment and couldn't reccomend a part that isn't a Yamaha item.

In conclusion, I got the impression that Yamaha certainly don't think their tensioners should be singled out as prone to fault. But, probably the most significant part of the conversation was that a noisy camchain might well be a worn chain rather than a faulty tensioner, I guess if the chain is beyond wear limits then perhaps it gets to a point where it is asking too much of the tensioner to keep it tensioned. It's possible that a manual tensioner could be used to unwittingly tension a knackered camchain so perhaps caution is required in using one and in an ideal world you should measure the wear on the chain before using one.
 Anyway, I bought a standard tensioner for £95 and I'll fit it and and forget about it.

[devilsyam]

£95 fookin quid I have 3 here you can have for nowt more money than sense me thinks lol

[Simon.Pieman]

£95 fookin quid I have 3 here you can have for nowt more money than sense me thinks lol

Makes sense to me and Yamaha too, mate.

[VNA - BMW Wank]

Interesting post Simon.  Googling aboot, it seems to be the later hydraulic tensioners that seem to have given em more of a headache.  And of course the Yamaha tech has to be very careful what he says to Joe Blogs over the phone as he knows it can end up on a bike forum!  Still interesting to read what he has to say though.

Amazing isn't it, decades after the Japanese gave us the over head cam UJM, they are still trying to sort out the cam chain tensioner.  Come on gives us the gear driven cams we want!  Bring back 2 strokes!  Anything without a cam chain!

The thought in my mind is that with the bikes getting older and older now (as is this owner ) will we start to see more cam chain tensioner failures.  And of course if it fails is it fatal or not?

I dunno.  Can see why folks are fitting manual tensioners, but I'd be worried I might be inviting other problems, ie not getting the right tension applied.  And why do all the manufactures avoid manual tensioners?

Anyway as my bike is now garaged, and my ancient garage is slowly moving towards becoming a half decent workshop,so rather than the material condition of my thou slipping year by year, it might just start improving from now on.  When I do start pulling bits off to restore em I might also pop a new auto tensioner on.

Ooooo and what other bike to purchase to keep the thou and the C90 company?

But naw I'm just not gonna worry about it too much. 

[sirgalahad3]

Hmm I tend to think Simons idea is good....
Because I think the standard tensioner is the best way to go and also that most second hand ones have been apart and no one knows what pre tension Yamaha put on the spring. I foolishly took mine apart to see how it works, see above posts, and wished I hadnt as I feel sure the spring was pre tensioned I cannot now be sure its back together properly. The only way I would now feel safe would to go pay 90 quid for a new genuine tensioner,  thats why I have a manual one fitted....Bugger!
As said before though,purely my own opinion and everyone to there own

[Borderraider]

My Gen 1 has done 39K and developed cam chain noise, the tensioner was fine the cam chain had stretched & worn.
I fitted both anyway, £99 for chain, £33 for tensioner. Can't see the point in fitting none standard parts when genuine parts aren't that expensive.

[solorider]

I have now fitted my manual tensioner, and the original tensioner could not be pushed in in anyway, but a worrying thing did happen though, I wound in the tensioner with the supplied tool, anyway the tool fell out but the tensioner did not spring out as it should have done !! but after turning it with the tool the tensioner started springing out as it should and did not stick again.
here is a picture of the tensioner I fitted to my bike

which I found was a better engineered one than another one I saw on eBay
 

[sirgalahad3]

Hi Solo,yes thats the one I have fitted. Quality isnt it.
I cannot make up my mind, plastic cap on or off?