Author Topic: Not again!! Cam Chain Tensioner Spring (Read 21479 times)

pilgrim · « **on:** 09 May 2013, 02:11:59 pm »

Like Dave Lister said in Red Dwarf:
How the smeg can the same smeg happen to the same guy twice?
The smegging spring in my cam chain tensioner has snapped again!!!!!!!!!!
Dont know what damage has occured this time. Bike was in warm up mode on the drive before going to work, then it just stopped. Thought I might not have put enough choke on, so pressed the starter and nowt. Starter motor whizzing round then clonk zero. Back in shed, lift with the wife.
Booked half a day and came home, first thing I did was take the tensioner out and sho nuff, broken spring

Have to have a more in depth look at the weekend, but last time it was nine bent inlet valves and a head swap

By coincidence, at the Bike Shed the other week I noticed someone had a bloody great bolt where the tensioner should have been. Who was that and why?
To any Newbie Gen 1 owners out there, dont worry about this, apparently its not a common fault, its just that I was really evil mass murdering son of a bitch in a previous existence, probably Hitler or someone

Yours
P. Pot. esq

devilsyam · « **Reply #1 on:** 09 May 2013, 04:03:58 pm »

Go manual then eliminate record motoru

pilgrim · « **Reply #2 on:** 09 May 2013, 05:04:01 pm »

Quote from: devilsyam on 09 May 2013, 04:03:58 pm

Go manual then eliminate record motoru

Yep thats what I was thinking

Guess it was you then, no surprises there then

How did you do it, or is that a trade secret?

Seen a manual one on Fleabay for about thity quid, but I'm a tight fisted Northern git, so will always go for the cheapest/ diy option.
PS. 'eliminate record motoru' ? what dat den?

devilsyam · « **Reply #3 on:** 10 May 2013, 07:58:28 pm »

the early r1 fits but you need longer or shorter bolts cant recall got mine from warpspeed racing but the ebay ones look better

PaulSmith · « **Reply #4 on:** 14 May 2013, 01:49:01 pm »

... but I'm a tight fisted Northern git, so will always go for the cheapest/ diy option...

You don't think that could have had anything to do with why it failed again?

Just kidding, Hope you get it sorted without too much damage

phil on a fazer · « **Reply #5 on:** 23 May 2013, 07:52:42 pm »

Are you supposed to service the cam chain tensioner??? i've heard a few horror stories of seized ones on the Fazer.

I dont really know what it does...well, it tensions the cam chain i imagine.

doesnt it do this automatically (spring loaded?) so should i be checking it isnt seized as my fazer is a keeper and i want her for the rest of my life!! (im 31)

pilgrim · « **Reply #6 on:** 24 May 2013, 01:38:26 am »

Good question Phil ( I'm also Phil BTW

)
Heres an answer. Sort of. Quite long.
Cam chain tensioners are one of those things that, through the years, have been troublesome on some bikes, and not on others. The first GPZ 900r's were notorious for having dodgy ones, and a few other models of bikes from various manufactures also had problems. Having said that, I have never had a problem with one on any of the bikes I've ever owned, and thats in 28 years of riding, and about half a million miles

Now, here comes the little problem that I can see with the Fazer one.
In the past when I have had occasion to remove cam chain tensioners from various bikes for whatever reason, they have all seemed to work on the same principle, which is a spring pushing a piston out from behind to tension the blade and the piston having splines on one side and a sprung toothed cam sort of thing which stops the piston from pushing back in. Simple really. If the spring fails in any way, the piston is locked in position and the first you would know about it would be a gradual increasing rattle from the cam chain as it wears and gets slacker but isnt being tensioned by the blade because the spring isnt gradually pushing the piston out to take up the slack.
With me so far? Phew.....
The Fazer one, or at least the two that I have now removed, dose'nt work like that. Rather than being a spring pushing the piston from behind, the spring is a bit like a minature slinky which is hooked over the end of the chain tensioner outer body, wraps around the piston and is hooked over the back end of the piston, under tension, and therefore PULLS the piston out, creating tension on the blade.If the spring fails at any point it will just close up and beome slack., doing sod all. Now, here comes the problem with this design. The piston isnt toothed, with a cam to lock it in place, so when the spring fails, it can just be pushed back in to the body of the tensioner, taking all pressure off the blade instantly, and then slap bang wallop slack cam chain flapping around, jumping teeth on the cam sprockets and then oh deary me disaster

When this happened the other week, I wasnt even riding my bike, it was ticking over on the drive at about 1300rpm, and its still managed to lock up the engine and bend valves etc. Fuggin ell!
Now as far as regards servicing the little bugger, it shouldnt really need it. Its a pretty simple device really, fed by oil from the engine, and should be nicely lubed by that. Both times I've stripped out knackered ones, they've been full of oil and looking fine, apart from the snapped springs, which are really thin. I dont know why its happened twice, first one at 26k, second one at 32k, maybe I have an issue with oil flow, but it does'nt look that way. I'm flummoxed, and very very pissed off

So, it looks like I'm going to be looking for another cylinder head, and rebuiling it again, but this time I'll be buying a manual cam chain tensioner from somewhere ( seen one on ebay) and hopefully eliminating the problem

Dont let my bad experiences worry you, its just one of those things and was bound to happen to someone. That would be me

Twice

Arse.
Sorry if that was a bit long winded, but felt the need to spout.
TTFN
Phil

pilgrim · « **Reply #7 on:** 24 May 2013, 01:44:47 am »

Forgot to add, if it had seized it wouldnt have been as much of an instant problem, just a slowly increasing cam chain rattle which would hopefully have been caught in time. Wish it had seized now, come to think of it.
Just my bloody luck!
Double arse.
$:\$

FazerRuss · « **Reply #8 on:** 24 May 2013, 08:27:27 am »

How do you know how to set the manual tensioners so they're the correct chain tension?

pilgrim · « **Reply #9 on:** 24 May 2013, 02:35:50 pm »

The camchain dont rattle!

But seriously, by taking a measurement of where the original is extended to, and then setting it to that length. There is a way of doing this involving a thin flat bladed screwdriver, a ten mill spanner, a small steel ruler and marker pen. From then on, its just a question of playing it by ear I suppose. Not had any experience of manual ones, but this seems to be the method.
Getting the horrible feeling I'm becoming far too familiar with Gen 1 cam chain adjusters. Need to break the cycle, but not literally, again.

phil on a fazer · « **Reply #10 on:** 27 May 2013, 04:14:00 pm »

pilgrim - good info, thanks very much!!!

pilgrim · « **Reply #11 on:** 28 May 2013, 01:17:46 am »

No problem

pilgrim · « **Reply #12 on:** 21 August 2013, 11:19:12 pm »

03 engine installed and officially back on the road as of Tuesday last week

Came out of work on Wednesday and pissed coolant all over the floor on start up. Lower coolant pipe on oiler cooler from old engine fractured. Got it home and started to undo the jubilee clip, pipe sheared off completely

No Gen 1 oil coolers anywhere to be found, but got one from a 2000 R1 which is supposed to be the same. Turned up Friday am.

Its not the same, its shorter. Oil cooler bolt too long by about 15mil. $:\$
Popped in to work on Sat morn and cut bolt down, then filed a shank in to it, by hand, for the 5 or 6 mil of bolt protruding from oil cooler that wasn't threaded. 2 hours later, job done, fitted, running like a dream

Manual cam chain tensioner working luverly.

Tools used; everything in my tool boxes plus my old skateboard from 30+ years ago in lieu of a trolley jack

Sometimes, weird shit from the past still comes in handy

Phil.

b1k3rdude · « **Reply #13 on:** 22 August 2013, 03:50:20 pm »

Quote from: pilgrim on 21 August 2013, 11:19:12 pm

Popped in to work on Sat morn and cut bolt down, then filed a shank in to it, by hand, for the 5 or 6 mil of bolt protruding from oil cooler that wasn't threaded. 2 hours later, job done, fitted, running like a dream

Got pictures, so the rest of us can use this neat little fix for when we can't find an FZS cooler..

ogri48 · « **Reply #14 on:** 23 August 2013, 06:40:20 pm »

respect due pilgrim, under adversity and getting shat on by the god of cam chain tensioners not once but twice, thats the sort of true brit spirit that got us thru the blitz! last one i had go was i think a cb900f in the mid eighties, didnt think they failed anymore. nicely done mate

pilgrim · « **Reply #15 on:** 23 August 2013, 09:49:37 pm »

B1k3edude, sorry pal, didn't think to take pictures, but if anyone ever needs to do it, its an easy talk through and pretty obvious when you see the parts in hand

ogri48, cheers pal, not the sort of task to be taken on by the faint hearted or spanner inexperienced type, but I've always had a 'give it a go' attitude, its the best way to learn. And cos I'm a tight fisted get.

Spannerhands · « **Reply #16 on:** 24 August 2013, 10:29:48 am »

Have you tried holding the tensioner blade against the chain with your finger through the tensioner hole whilst manually turning the motor? If you have any tight spots on the cam chain the blade will move back and forth excessively which might explain two broken springs. The manual tensioner could be exerting a lot of stress on the valve train components if this is the case.

Hedgetrimmer · « **Reply #17 on:** 24 August 2013, 01:06:53 pm »

Quote from: Spannerhands on 24 August 2013, 10:29:48 am

Have you tried holding the tensioner blade against the chain with your finger through the tensioner hole whilst manually turning the motor? If you have any tight spots on the cam chain the blade will move back and forth excessively which might explain two broken springs. The manual tensioner could be exerting a lot of stress on the valve train components if this is the case.

Just when you thought it was safe to fit a manual tensioner....

Spannerhands · « **Reply #18 on:** 24 August 2013, 01:34:03 pm »

Never the less. Think I'll get a manual adjuster. My bike's done 53000 miles!

Simon.Pieman · « **Reply #19 on:** 24 August 2013, 04:11:32 pm »

Quote from: Spannerhands on 24 August 2013, 01:34:03 pm

Never the less. Think I'll get a manual adjuster. My bike's done 53000 miles!

Mine's done 56,000 but I don't think I'll be getting one. If the standard tensioner 'fails' it is proceeded by the camchain gettig noisier before jumping sprockets, the same symptoms that signal it's time to adjust your manual tensioner incidently. So, simply listen for your chain getting noisier and then replace the tensioner with a new one, the standard tensioner doesn't fail suddenly -it can't because it doesn't retreat beyond the last ratchet point.
Manual tensioners only let you know they need adjusting when they become noisy -ie when they arn't working and need adjusting, neglect it just once and you suffer the same result of a standard tensioner doing exactly the same.

VNA - BMW Wank · « **Reply #20 on:** 24 August 2013, 08:48:55 pm »

Oh boy, here we go again!

Hedgetrimmer · « **Reply #21 on:** 24 August 2013, 08:57:21 pm »

So, I've decided to eliminate my cam chain. That way, I won't have a tensioner that can fail. I've also decided not to use oil anymore, as it might prevent my engine from running in properly. I've also given up with petrol, cos it blew holes in my pistons. So I've taken those out as well. And the EXUP valve won't be sticking anymore, I guess. Same for the brake calipers. And to prevent any corrosion in the winter, I've dipped the whole bike in a rubber solution. Except the tyres. I'd already taken those off cos I'm scared of punctures.

Anyone know how I can get a bit more performance out of it?

pilgrim · « **Reply #22 on:** 25 August 2013, 01:08:38 am »

Simon. Pieman. Sorry to piss on your chips here, but I'm afraid to say that the Gen 1 Fazer Thou cam chain tensioner doesn't have the ratchet system to which you are referring. I've seen those on many bikes in the past, and if it had one it would have saved me an awful lot of time/trouble/money

Simple fact is, when the spring lets go all pressure is taken off the tensioner piston instantly, no gradual rattles, no warning signs, just clonk dead! This most recent time it happened to me, the bike was ticking over on the drive sweet as a nut, and then it just stopped. Dead.
Nature takes its course, the cam chain instantly starts to flail around because the blade has no way of retaining tension, and it gets expensive. $:\$
Trust me on this, the cam chain tensioners on these have a serious design flaw, and if you are unlucky enough to have it rear its ugly head, which is a rare occurrence, I'll grant you, you will wish it was ratcheted, or some other method by which a tiny little shitty spring made out of the thinnest wire you have ever seen can suddenly wreck you're engine.
It wont happen to me again, because I have now eliminated the spring from the equation. Think I'll be sticking with my manual one, and wary ear

Don't say I didn't warn you

devilsyam · « **Reply #23 on:** 25 August 2013, 03:29:24 pm »

http://www.ebay.co.uk/itm/Yamaha-FZS-1000-Engine-Spares-Or-Repair-/171113039591?pt=UK_Motorcycle_Parts_13&hash=item27d721c6e7

another dead un

Simon.Pieman · « **Reply #24 on:** 26 August 2013, 09:16:36 am »

Quote from: pilgrim on 25 August 2013, 01:08:38 am

It wont happen to me again, because I have now eliminated the spring from the equation. Think I'll be sticking with my manual one, and wary ear
Don't say I didn't warn you

Ok I stand corrected!