Resetting the L4 Cam Chain Tensioner

Fisher · Post by **Fisher** » Sat Jul 07, 2012 5:06 pm

Hi all,

I have searched the forum, looked at the manuals, and checked the internet.
I don't seem to be able to find any detailed info on resetting the L4 cam chain tensioner.

I know that on the newer models, there is a lock nut you remove, and insert a piece of wire in to to hold the ratchet down whilst you inset it back in to the engine, however on my L4 model (which is different) I do not have this.

Am I correct in saying, that I need to remove the bolt from the bottom, to remove the springs and insert it with the ratchet down, then re-install the springs once back in place?

I know I probably shouldn't of touched it without knowing what I am doing. My fault, I don't really have a huge amount of money to spend at a garage, just for them to charge me Â£30 for what is essentially a very easy fix.I watched videos on YouTube, and thought I knew what I was doing, until I realised my tensioner is what appears to be the older type. At least I haven't tried putting it back in without resetting it!

Also, some places on the internet say to manual crank the engine a couple times to get it to set properly, and other places say just start it up. Should I be manually cranking it?

Much appreciated,
Fisher.

Fisher · Post by **Fisher** » Sat Jul 07, 2012 5:23 pm

And in case you wanted to hear the full story as to why I removed it...

My bike makes a horrendous rattle between 3.5k and 4k RPM which I suspect is the cam chain.
So I figured the first port of call is to reset the tensioner, and then to see where it adjust too so I can work out roughly how much life is left in my chain.

The bike only JUST came out of the garage (last week) where they adjusted all the valve clearances, and also checked the life of the chain, telling me it was fine.

If this doesn't work, I will be taking it to the garage to sort out, as I don't want to fiddle any more than removing and resetting the tensioner.

Randle · Post by **Randle** » Sat Jul 07, 2012 9:52 pm

I realize you have removed the tensioner, but, from the beginning.....

To remove the tensioner I would first remove the large bolt from underneath the tensioner.
Remove the 2 springs that should fall out (one spring inside the other).
Then remove the 2 cap head bolts that hold the tensioner on, with an allen key. Then pull the tensioner out of the bike.

To check if the tensioner one way ratchet mechanism is working, try to push the tensioner rod down into the body of the tensioner with your thumb.
It should not move until you press the spring loaded ratchet mechanism that you can see engaged against the serrated edge of the tensioner rod.
When you press, and hold, that spring ratchet mechanism in, you should be able to push the tensioner rod down into the tensioner body.
Cam chain tensioners fail when that ratchet mechanism fails to stop the rod from traveling backwards when it is engaged.
You should hear the ratchet click many times when you pull the rod out.

To re-insert the tensioner back in the engine, first push the tensioner rod all the way into the body. (very important to reset the tensioner to this position before fitting it back in the engine.)
Push the tensioner into the engine, then fasten it in with the 2 cap head bolts. Make sure the 2 cap head bolts are wound all the way in.
Then insert the 2 springs and the large bolt in the bottom centre of the tensioner.
You may hear the tensioner ratchet clicking as the rod moves out under the spring pressure as you tighten the large bolt.

It is a good question as to whether you should manually turn the engine over, allowing the tensioner to take up chain slack, or just start the engine.?? Anybody??
I would turn the engine over manually to be safe, especially if you wanted to see the position of the tensioner, as you will need to remove the right hand engine cover anyway.
To turn the engine over use a 19mm socket on the end of the ignition rotor, on the right hand end of the crank. Only turn the crank clockwise.

You certainly sound like you are being careful, so I am sure you will get this right.

Fisher · Post by **Fisher** » Sat Jul 07, 2012 11:10 pm

Ha!
I LITERALLY just did it, then came back to find this! Typical.

Well, I decided to just go for it. I couldn't see any other way.
I had already removed the tensioner, so I had to hold it in a vice to get the 12mm bolt out from the bottom.

I had already worked out that it was working, because the ratchet was holding it firm.
I re-inserted as per your instructions, so am fairly happy I did it all correctly.

Doesn't help my nerves as I am about to start it!
The cam chain feel very very firm, as it should.

I have about 5mm of movement before the tensioner hits the casing so I should probably order a new chain this week and have it replaced fairly soon...

I shall start it up, and hopefully I put it all back together properly!
And then I should be able to take it for a test ride shortly to see if it has resolved my rattle problem.

Although, once I run the engine, I may just take the cover off again to see if it has adjusted any further!
Perhaps the springs in the tensioner has worn?

I am expecting the chain to be worn, since I am now on 31k miles, and I have no paper work indicating a chain change at any point...

JulianWerner · Post by **JulianWerner** » Tue Nov 06, 2012 11:41 pm

Hi. I Just bought a Kawasaki ZXR 400 1991, and i read somewhere in this forum that you should change it at 36.000 (??)

I was visiting some other forums in my country, (norway) and they said cam chains alomost never wear out.
I wonder about the same thing..

Mine has gone 35.800 KM, and i wonder if i have to do something with it ? (mechanical speaking)

Randle · Post by **Randle** » Wed Nov 07, 2012 1:00 am

Have a read of the sticky 'new came chain fitting'.
There are a couple of pictures at the bottom of the page to help judge if your camchain is near the end of its life.
But if the camchain isn't making any rattling noises on tickover then don't worry about it.
I wouldn't change it for the sake of it, unless you are doing other engine work.

Driift · Post by **Driift** » Wed May 06, 2015 7:52 pm

Fisher,

I am experiencing a similar rattle but between about 4-5K rpm, it only happens there and goes away above and below. did you ever find out what was the cause of the rattle. Mine sounds more like a loud vibration that comes on at 4K and off around 5500. I reset the cam chain tensioner and it is still doing it, I was thinking a valve but it doesn't make sense as I would hear a valve throughout the RPM range.

Did you figure what was causing the rattle?

Tim

JamieNeve · Post by **JamieNeve** » Thu May 07, 2015 3:25 pm

Driift wrote:Fisher,

I am experiencing a similar rattle but between about 4-5K rpm, it only happens there and goes away above and below. did you ever find out what was the cause of the rattle. Mine sounds more like a loud vibration that comes on at 4K and off around 5500. I reset the cam chain tensioner and it is still doing it, I was thinking a valve but it doesn't make sense as I would hear a valve throughout the RPM range.

Did you figure what was causing the rattle?

Tim

Replace your exhaust header gaskets, this is a common symptom that they need replacing. They only cost around £3.50, and are very easy to replace.. Remove side fairings, remove top 2 radiator bolts and lean it out of the way, loosen exhaust headers, remove old gaskets and put new ones in. Tighten to torque specified in manual (I found I had to do them a bit tighter otherwise they loosen themselves.)

Hope this helps,

Jamie

Driift · Post by **Driift** » Thu May 07, 2015 6:03 pm

Jamie,

I really appreciate the response, I will give it a go and post the result. THANKS so much from the USA! Yeah, I have two zxr400s. Have owned just about every collectible bike around, but these ZXRs are so freakin fun to ride and they corner so well, its amazing. Again, really appreciate the response!

Tim

JamieNeve · Post by **JamieNeve** » Thu May 07, 2015 10:36 pm

They are awesome little bikes! Let me know how you get on, hopefully no further action is needed!

Jamie

TurkishJordo · Post by **TurkishJordo** » Fri May 08, 2015 12:41 am

Mine was making horrible "vibration" noises at exactly 5.800 rpm, turned out to be very blocked main jets (all 4!), but no other fuel problems... was very strange! 2 bottles of carb cleaner later and she is now smoother than ever, very nice to ride

TurkishJordo · Post by **TurkishJordo** » Fri May 08, 2015 12:47 am

[...] some places on the internet say to manual crank the engine a couple times to get it to set properly, and other places say just start it up. Should I be manually cranking it?

Much appreciated,
Fisher.

19mm wrench on the timing plate, turn clockwise a few times and that will set the tensioner, better safe than sorry. If the tensioner wasn't broken, and isn't touching the casing (full stretch) then there is still some life left in your cam chain, however if the cam chain has stretched then your exhaust timing (double check) will be slightly off due to the chain being longer (worn).

Driift · Post by **Driift** » Mon May 11, 2015 6:43 am

JamieNeve wrote:They are awesome little bikes! Let me know how you get on, hopefully no further action is needed!

Jamie

Jamie,

Do you know the torque specs for the header bolts? I saw to figures in the service manual ..... outlet pipe mounting bolt 4.9 NM???? seem right?

Tim

JamieNeve · Post by **JamieNeve** » Tue May 12, 2015 10:57 am

You are right, it's an odd one. The manual doesn't use plural, just "outlet pipe mounting bolt" 4.9Nm in L manual, and 8.8Nm in the H manual. If you look on the actual diagram too, it does not label the bolt for use with the key so it is a tricky one.

I found that 8.8Nm was way to loose for mine, so when I did mine I resorted to doing them until they were pretty tight (not overly tight, but not loose.) So yeah, I'm pretty certain 4.9Nm cannot be even close, so would recommend using your own judgement, just don't start going crazy with your wrench!

Sorry I can't be of much help, it's been brought up before that this is a bit of a blind spot in the manuals!

Driift · Post by **Driift** » Wed May 13, 2015 9:09 pm

Am I to assume the flat slide faces the pipes and the lipped side seats within the engine? Just want to do this right the first time and maybe someone reading this will have their answer too. Thanks. Tim

www.zxrworld.co.uk