Timing Tensioner Chain

[MS]

Yes, this is what it looks like. However after changing i still faced the problem of RPM, whereby the RPM will drop if idle to long and will result of my bike dying off.. Does it matter with my carb setting?

 

I believe the chain slack tension may not have been dealt with. It could be too loose or too tight. Consequences following these are catastrophic. This is not the first time I've encountered this. I personally know 2 guys who apparently 'tightened' their timing chain on a R6 and a G6K4 by adjusting the cam chain tensioner. The R6 did not have nay problem but the G6K4 could not hold the idling.

 

I strongly believe the reason was because the R6 rider was fortunate enough that the timing chain slack had been adhered to coincidentally. But the G6K4 had over tightened it. I advised him to go to the workshop and do a top overhaul which the labour will naturally cover the chain slack tension adjustment to factory specs. The problem was solved after that. It was not really a pricey lesson as his mileage had already exceeded 40,000km. Anyway one way or another, it's about time to do it.

[MS]

Much has been spoken about engine timing. But what is engine timing exactly? Perhaps I can make an explanation here.

 

The internal combustion engine that operates on the otto cycle has the following process.

(1) Induction – Air and fuel mixture will be induced into the combustion chamber

(2) Compresison – piston will compress the chamber to a certain small volume which can even reach 12 times smaller for some powerful engines (compression ratio)

(3) Combustion – spark plug ignites the compressed air fuel mixture

(4) Exhaust – the combusted mixture is pushed out of the combustion chamber.

 

http://i115.photobucket.com/albums/n298/arakyo/4zylsingle.jpg

The above drawing is scanned from the Bosch Automotive Handbook for Automotive Engineers (7th edition) page 483

 

Legend:

E = Exhaust

EO = Exhaust opens

EC = Exhaust closes

I = Intake

IO = Intake opens

IC = Intake closes

TDC = Top Dead center

OTDC = Overlap Top Dead Center

ITDC = Ignition Top Dead Center

BDC = Bottom Dead Center

IP = Ignition Point

 

Refer to the picture as I guide you through a single cylinder 4 stroke internal combustion petrol engine with 2 valves. (1 intake and 1 exhaust) I try to explain it as simple as possible.

 

Look at the part labeled as IO. The intake valve begins to open. In OTDC, the piston is thrown upwards till the maximum. The exhaust valve and inlet valve at this OTDC is slightly opened. Exhaust valve is on the way to close, inlet vale is on the way to open. Slide down the circle in the diagram as the piston is thrown downwards. Air and fuel mixture is induced into the combustion chamber. Until the point BDC which means the piston is fully at the bottom of the stroke. About 40~60Degrees piston move upwards after BDC, inlet closes (IC). Take note piston is still being thrown upwards. This is now the compression stroke. Until the point about 0~40degrees before TDC, the spark plug ignites (IP) The piston will then reach the TDC again. (ITDC). Now it’s the combustion stroke and so the piston is forced downwards by the combusting fuel and air mixture. While on the way down, about 46deg~60Deg before the BDC, the Exhaust valve opens (EO) Until the point when the piston reaches BDC, the piston will now be thrown upwards by the crankshaft throw again for the exhaust stroke. Take note exhaust valve is opening now. Slide up the circle in the diagram as the piston move upwards until the (IO) inlet valve opens. Take note this is the overlapping stroke with the inlet on the way to opening while the exhaust on the way to closing as the cam shaft lobe is on the declining side. Eventually the exhaust valve closes. However not before the Inlet valve begins to open and restart the whole cycle again.

 

The anatomy of this as shown in the VAG diagram, the camshafts are in charge of opening and closing the valves. The crankshaft is in charge of controlling the piston location and stroke. The force that maintains the rotation is contributed by the crankshaft throw. All these are synchronized by the timing chain/belt/cam gear.

 

This is what happens in one cylinder during operation. However, most big bikes are running on multiple zyl.

 

We shall talk about a inline 4zyl, 4 stroke engine. With firing order 1342.

http://i115.photobucket.com/albums/n298/arakyo/4zyltiming.jpg

Legend:

I = induction

C = compression

P = Combustion

E = Exhaust

 

The procedure of the 4 strokes always come in this order.

 

In S1 (stroke 1), zyl 1 is in power stroke because the first firing order is 1. Therefore the sparkplug ignites in the 1st zyl at the 1st stroke. Next, followed by the 3rd zyl which the 3rd spark plug over your engine will igite next. Followed by the 4th zyl and the 2nd zyl. We count the numbers starting from the cam chain/belt/gear as #1 zyl.

 

After that, fill in the boxes with the following strokes and you will have a stroke diagram of a 4zyl inline engine. This table only works for this arrangement because inline 4 strokes have 180deg crankshaft throw. Now imagine the process of the first diagram taking place in orders of 1-3-4-2. And there you have a 4 zyl engine.

 

The exact table of a 6 zyl, 2 zyl, 5 zyl varies and I don’t have the table of the specific engines. But I can share that the 6zyl has a firing order of 1-5-3-6-2-4.

 

In order to obtain such a perfect synchronized operation, the timing chain must be well tensioned given the stipulated slack must be upheld. Therefore, if the cam chain tensioner is loose or too tight, it affects the operationability of the engine and thus lead to high fuel consumption, premature wear of engine parts, lower power, engine unable to hold idle, engine stall or engine unable to start.

 

I hope these information is good. If you are interested, I recommend you to do one overhaul process yourself. Equipped by the theory knowledge of engine timing. Engine timing is the foundation of engine overhauling skills. Once you understand that, the rest will slowly fall into place as you work on a proper engine. For a start, I recommend a 4 stroke inline 4 zyl engines.

 

Sorry, I just realized I typed many zyl. This is the short form in German for Cylinder.

[Phang]

MS, I see your point. If a timing chain tensioner plunger is extended to its maximum stroke (the chain slapping/rattling noise will lead the rider to the workshop), chances that the timing chain is already wear beyond its service limit is high.

 

The mechanic should measure the timing chain wear to determine that. But most of the time the plastic chain guide wears out before the chain does

 

Bikes with automatic cam chain tensioner, riders will change it to a manual one. Those with manual one, want to change it to an automatic one.

 

We can never be happy

 

 

That’s very true, when you have a manual (fill in whatever here) you want an automatic. When the engineers made an automatic for you, you want the manual again

[MS]

MS, I see your point. If a timing chain tensioner plunger is extended to its maximum stroke (the chain slapping/rattling noise will lead the rider to the workshop), chances that the timing chain is already wear beyond its service limit is high.

The mechanic should measure the timing chain wear to determine that. But most of the time the plastic chain guide wears out before the chain does

That’s very true, when you have a manual (fill in whatever here) you want an automatic. When the engineers made an automatic for you, you want the manual again

 

Yes exactly. But this seldom happens unless it's a machine with considerable age and extreme usage. Given the model of the TS's machine, I think it's about time.

 

I think the average consumers don't really bother about the chain slapping. More likely the loss of power, black smoke, unable to hold idling rpm, engine stall repeatedly. All these that really become intolerable poise the owners to go to the workshop.

 

All these can be attributed by running in procedures that did not adhere to factory instructions, extreme usage, missing of scheduled maintenance, wrong parts used (ie. wrong part number even though dimensionally it fits in)

 

I can only do so much here as my information is only very general. My specialization is not power generation, even if it is, the corp comms guidelines forbid me to engage the public with my identity known. Also elaborate product details are to be withheld due to strategic reasons too.

 

But if anyone is interested to learn more about petrol power generation, you can learn from one of the best engine suppliers in the world; Cosworth. Or email them directly at [email protected] But do visit their website.

[Orleng]

Yes exactly. But this seldom happens unless it's a machine with considerable age and extreme usage. Given the model of the TS's machine, I think it's about time.

 

I think the average consumers don't really bother about the chain slapping. More likely the loss of power, black smoke, unable to hold idling rpm, engine stall repeatedly. All these that really become intolerable poise the owners to go to the workshop.

 

All these can be attributed by running in procedures that did not adhere to factory instructions, extreme usage, missing of scheduled maintenance, wrong parts used (ie. wrong part number even though dimensionally it fits in)

 

I can only do so much here as my information is only very general. My specialization is not power generation, even if it is, the corp comms guidelines forbid me to engage the public with my identity known. Also elaborate product details are to be withheld due to strategic reasons too.

 

But if anyone is interested to learn more about petrol power generation, you can learn from one of the best engine suppliers in the world; Cosworth. Or email them directly at [email protected] But do visit their website.

 

 

Hi MS, seems like you know quite a fair bit about engines.

 

Would like to check w you on 2 things regarding the CCT.

 

1) If i frequently hit false neutrals and the engine rushes into redline very quickly with no load, is there possibility of damaging the CCT, since there's a chance the chain will be flailing around? Or is that unlikely to happen one way or another regardless of whether the engine revs high with no load? Was reading somewhere that a high-revving engine when backed off suddenly can cause slack in the CC and allows it to slap around, damaging the CCT in the process.

 

2) If i decide to replace the CCT, would i then have to open the head to adjust chain slack? E.g., install new CCT then after releasing the pinch bolt holding the CCT retracted, allowing the CCT to engage the tensioning guides. Then at that point, with all slack taken up, adjust the cam sprocket based on the timing marks?

Or can i do a direct swap of CCT and assume that upon removal, the slack developed will be taken up by the same amount with no movement of the cam sprocket upon installation of the new CCT.

e.g. there is enough tension from compression to hold the crankshaft sprocket in place?

 

I've been considering changing the CCT due to a gradual build up of noise coming from the chain-side, but not quite willing to send it for top overhaul.

 

2B bike btw.

 

Would really appreciate some feedback n comments!

 

PS: could you PM me if too much details/info to be posted here?

 

thanks!

[MS]

Hi MS, seems like you know quite a fair bit about engines.

 

Would like to check w you on 2 things regarding the CCT.

 

1) If i frequently hit false neutrals and the engine rushes into redline very quickly with no load, is there possibility of damaging the CCT, since there's a chance the chain will be flailing around? Or is that unlikely to happen one way or another regardless of whether the engine revs high with no load? Was reading somewhere that a high-revving engine when backed off suddenly can cause slack in the CC and allows it to slap around, damaging the CCT in the process.

 

2) If i decide to replace the CCT, would i then have to open the head to adjust chain slack? E.g., install new CCT then after releasing the pinch bolt holding the CCT retracted, allowing the CCT to engage the tensioning guides. Then at that point, with all slack taken up, adjust the cam sprocket based on the timing marks?

Or can i do a direct swap of CCT and assume that upon removal, the slack developed will be taken up by the same amount with no movement of the cam sprocket upon installation of the new CCT.

e.g. there is enough tension from compression to hold the crankshaft sprocket in place?

 

I've been considering changing the CCT due to a gradual build up of noise coming from the chain-side, but not quite willing to send it for top overhaul.

 

2B bike btw.

 

Would really appreciate some feedback n comments!

 

PS: could you PM me if too much details/info to be posted here?

 

thanks!

 

Thank you, I am utterly flattered by your comments. But I am also a learner with a modest bit of experience only.

 

The cam chain tensioner is something like an extra piece of material protruding out to create a tension on the chain. The chain is given its stipulated amount of tension on the camshafts and then the cam chain tensioner at the side creates another tension on the chain to control the slack. This ensures proper synchronization on the camshaft and the crankshaft which runs the valve timing and the piston location respectively. The article is true. At the same time, with no load or with load, revving at the red line is detrimental to engine lifespan not only the affecting the chain tension, also the combustion chamber’s dimentions, crankshaft bearing shell nip etc etc. That’s why, it doesn’t matter as high rev is detrimental to the engine on the whole. However proper maintenance and proper running adherence can prolong the lifespan as the wear rate in regards to the engine lubrication circulation, oil pressure, dimensions are well taken care of. That is why it is important to follow manufacturer’s run in recommendations and not to prescribe the procedure anyhow.

 

On the practical side, when we buy the bikes, I will never believe anyone who says he had never revved till the red zone before. Engines don’t fail so easily nowadays. If your engine has not clocked tremendous amount of working hours, you can save your money. Also, it is a 2B bike. If you intend to sell the bike and upgrade, also you can save the money.

 

Chain slack is adjusted with the cylinderhead off. So you can see the chain itself. I think the timing mark you refers to is the one that acts as a ‘complimenting gauge’ in response to the slack on the chain that you adjust in accordance to factory specs. But I don’t recommend you to replace the cam chain tensioner yourself unless you run a workshop. The chain slack is predefined by manufacturer. This pre-determined value is factory specified. Adherence is mandatory. A proper workshop mechanic specifically trained or experienced with your brand of motorcycle should know the specified values. Too much or too little slack and lead to the lack of capacity to maintain synchronization which leads to loss of power and even seriously damaging your engine.

 

Seriously speaking, there is no way things can be done ‘cheap and unprofessionally’. I know people who rush to ‘tighten’ their cam chain tensioner on the GSXR600K4 and end up losing power and unable to hold idling RPM. Eventually having to do a top overhaul. Fortunately for him, he was on the brink of reaching scheduled maintainance. Unless you have the determined specs, the spares and tools. I really advise you to bring it to a workshop. If you are unwilling to spend the money, then there is little you can do.

 

But if you decided to set aside money for it, go for the top overhaul. Ask for some complimentary tuning, engine oil/oil filter or spark plugs. Or even air filter. You have to change them anyway. Also, you get the warranty for the service. On the long run you benefit from it.

 

I hope I have been of some help.

[Wen gege]

changin timing tensioner can be done easily.

1st, get the correct model tensioner for your bike model.

2nd, ask the shop if the tensioner required any gasket.

3rd, get the tools required to open your tensioer and some clean cloth to clean your brand new tensioner before install in it.

4th, warm up your bike before doin any installation. it's important to do so cuz chain contract when cool. so you need to warn the chain before changing.

 

i dun know is urs required any gasket, but i dun have it for mine.

 

i had change my tensioner myself on my K5 1000. Those adjustable type.

some say good, some say bad. it's all base on oneself. adjustable tensioner can be adjustable by yourself any time.

however, note to be taken.

**DO NOT OVER TIGHTEN THE TENSIONER** as you will push the chain deeper inside. this will affect your riding.

 

pls correct me if i m wrong, but pls DO NOT FLAME ME.LOL.

ride safe guys.

peace

[jtzx]

woo woo woo.. chim chim sia.. see til blur/.

[Orleng]

MS and Wen Gege, thanks to both of ya for the information ya'll have dispensed. Was thinking of going the DIY route and learn a few things up close n personal with the engine at the same time, e.g. valve cleareances and other such things.

 

It's all very well to read about it, but when it comes to the nuts n bolts, nothing beats a good hands-on session eh? I guess it'd make more sense to experiment on a cheap 2B bike and be familiar with enginges before eventually going on to tinker on bigger bikes. At least a 2B bike is cheap(er) to repair/service should i mess up horrifically.

 

Will prolly be looking to acquire some tools first, then slowly get to breaking everything apart.

 

First thing to do when i do, is get that freaking annoying ticking sound fixed! I love taking things apart, shouldn't be hard to figure out how with a little elbow grease n your instructions!

 

MS, i was thinking of just swapping out the CCT and leave the chain alone. For the stock auto-adjuster one of course. So i won't be doing any manual adjustments to it. So, i guess, my question is, when i remove it, the slack that it's holding up will be released. Will i need to open the head to make sure that the cam sprocket hasn't rotated to be out of timing? Or will the installation of the new CCT bring the slack back to the proper position? Dunno if i make any sense.

 

In otherwords, was wondering in my head, say, the chain has around 1inch of play back n forth. when i take out the tensioner, will this slack allow the cam sprocket to rotate like say, maybe forwards or backwards 10degrees(arbitrary number for example purposes). If it does, when i reinstall a new CCT, will this slack be taken up properly, or will, say, maybe some of the slack being taken up come from rotating the crankshaft-side sprocket, thus allowing the two cam sprockets to run "out-of-time" with one another? or will be crankshaft-side sprocket be locked solid by the resistance from the engine?

[MS]

MS and Wen Gege, thanks to both of ya for the information ya'll have dispensed. Was thinking of going the DIY route and learn a few things up close n personal with the engine at the same time, e.g. valve cleareances and other such things.

 

It's all very well to read about it, but when it comes to the nuts n bolts, nothing beats a good hands-on session eh? I guess it'd make more sense to experiment on a cheap 2B bike and be familiar with enginges before eventually going on to tinker on bigger bikes. At least a 2B bike is cheap(er) to repair/service should i mess up horrifically.

 

Will prolly be looking to acquire some tools first, then slowly get to breaking everything apart.

 

First thing to do when i do, is get that freaking annoying ticking sound fixed! I love taking things apart, shouldn't be hard to figure out how with a little elbow grease n your instructions!

 

MS, i was thinking of just swapping out the CCT and leave the chain alone. For the stock auto-adjuster one of course. So i won't be doing any manual adjustments to it. So, i guess, my question is, when i remove it, the slack that it's holding up will be released. Will i need to open the head to make sure that the cam sprocket hasn't rotated to be out of timing? Or will the installation of the new CCT bring the slack back to the proper position? Dunno if i make any sense.

 

In otherwords, was wondering in my head, say, the chain has around 1inch of play back n forth. when i take out the tensioner, will this slack allow the cam sprocket to rotate like say, maybe forwards or backwards 10degrees(arbitrary number for example purposes). If it does, when i reinstall a new CCT, will this slack be taken up properly, or will, say, maybe some of the slack being taken up come from rotating the crankshaft-side sprocket, thus allowing the two cam sprockets to run "out-of-time" with one another? or will be crankshaft-side sprocket be locked solid by the resistance from the engine?

 

 

The Cam Chain Tensioner merely retains the stipulated tension on the chain. You will need to check with the official manual how much is the chain slack defined by factory. Are you using a 2B 4 stroke engine? Your engine layout and camshaft layout affects the way you measure your chain slack. So don't fool around with it.

 

I think what you need to do is not to ask in the forum. Via words, there's only so much we can do.

 

When I started out I went to a trusted workshop and did it hands on. I bought the official workshop repair manual and went to the workshop I trusted, bought the spares from them, and did it myself. Buying spares from the workshop is very important, give them business and they will feel better when teaching you. And I always buy more than I am supposed to. For example when I wanted to replace the sprockets assembly, I bought the whole assembly from them (front + rear sprockets + chain) and a set of brake pads. What has brake pads got to do with me changing sprockets? Nothing. Just wanted to make the workshop feel better. Anyway I will need to use it one day. If I need help I will ask the workshop mechanics to tell me where I went wrong.

 

By doing it there, you will learn what are the tools you should invest in. You should also be accustomed to the ways people call the tools ie. Number 17, number 19 combi spannar, flat tip, Yeoh-Tow (swinging head socket combi spanner), socket, T bar, hollow bar (For leverage extention when dismantling, but please don't use this when re-installing) etc etc.

 

One of the fastest way to train mechanics is to first equip with some classroom lectures knowledge, he must follow a 'master' as an apprentice. As time goes by, you will change masters if you work in a large workshop like CDGE, BM, C&C etc. And eventually you will find your specialization. I used to specialize in diesel engines. And even so, I can tell you, overhauling engines are rare. Due to obvious reasons like costs and downtime. At most we will merely do a top overhaul, FIP replacement, cooling system diagnosis. But now my specialization has changed following the where I work which I cannot say. I know there're some experts here who can easily guess where I work and even pin point to who I am if I reveal.

 

For you, instead of touching on your engine, maybe you want to start off with simpler components first. Get to learn them before you venture into engines. Maybe you can start by changing your own EO, oil filter, spark plugs, replacing brake pads, bleed your dot4, replace light bulbs, speedometer cables, sprocket assembly, overhaul your suspensions starting from non adjustable telescopic forks. Many shock absorbers require specs like amount of hydraulic oil and the grade of the oil.

 

sorry been talking too much. But if you want to do it, don't do a 1/2 phark job. Do it right once and good. My advise is go learn from a workshop

[MS]

http://www.cosworth.com/shop_item.php?productid=45

 

Please click the above for a view on the timing chain tensioner. source taken from Cosworth.

 

Attached is the picture of the timing chain and tensioner for Cosworth Duratec Cam Drive.

[Yamaha]

MS and Wen Gege, thanks to both of ya for the information ya'll have dispensed. Was thinking of going the DIY route and learn a few things up close n personal with the engine at the same time, e.g. valve cleareances and other such things.

 

It's all very well to read about it, but when it comes to the nuts n bolts, nothing beats a good hands-on session eh? I guess it'd make more sense to experiment on a cheap 2B bike and be familiar with enginges before eventually going on to tinker on bigger bikes. At least a 2B bike is cheap(er) to repair/service should i mess up horrifically.

 

Will prolly be looking to acquire some tools first, then slowly get to breaking everything apart.

 

First thing to do when i do, is get that freaking annoying ticking sound fixed! I love taking things apart, shouldn't be hard to figure out how with a little elbow grease n your instructions!

 

MS, i was thinking of just swapping out the CCT and leave the chain alone. For the stock auto-adjuster one of course. So i won't be doing any manual adjustments to it. So, i guess, my question is, when i remove it, the slack that it's holding up will be released. Will i need to open the head to make sure that the cam sprocket hasn't rotated to be out of timing? Or will the installation of the new CCT bring the slack back to the proper position? Dunno if i make any sense.

 

In otherwords, was wondering in my head, say, the chain has around 1inch of play back n forth. when i take out the tensioner, will this slack allow the cam sprocket to rotate like say, maybe forwards or backwards 10degrees(arbitrary number for example purposes). If it does, when i reinstall a new CCT, will this slack be taken up properly, or will, say, maybe some of the slack being taken up come from rotating the crankshaft-side sprocket, thus allowing the two cam sprockets to run "out-of-time" with one another? or will be crankshaft-side sprocket be locked solid by the resistance from the engine?

 

aiyo....tick tick sound. troubleshoot 1 by 1 if tick tick come back...montior it

 

1) change EO first

2) valve adjustment

3) change camchain tensioner (i use auto)

4) change chain

5) top overhaul liao haha or just live with it or mayb some1 has better idea

[Aalex82]

sometimes worn off header gasket oso produce tick sound..

[devilsadd]

1) what if i don care abt the tick tick sound??? wil my engine be damage???

 

 

 

2) adjusting or change the timing tensioner chain can be done at any bike shop???

 

 

 

sorry guys, for those question...as i've no knowledge for the timing tensioner chain...

[Paladin]

1) what if i don care abt the tick tick sound??? wil my engine be damage???

 

 

 

2) adjusting or change the timing tensioner chain can be done at any bike shop???

 

 

 

sorry guys, for those question...as i've no knowledge for the timing tensioner chain...

 

1) one day the increased off timing will cause valve to hit piston. then, good luck liao.

 

2)should be bah (at least for those common models)

[devilsadd]

oh.. okok... than does the repair of the timing tensioner chain cost very high??? hmmmm

[devilsadd]

hi everyone... i'e changed the cam tensioner ( if i'm not wrong )... but y does the tick sound stil have???