High mileage valve adjustment - a good time to change the cam chain?

[Mzee]

My bike has 75,000km. I took it for valve checking and the Yamaha mechanic did no adjustment saying they were within specs. I must inform you that no previous valve adjustments have been done. I agree with the others that if the bike is running, no need to fix what has not failed, but again prevention is better than cure.

 

[dcstrom]

Well y'know... since I asked this question, I've been back to the US (from the UK), bought a bunch of stuff to resupply for the trip... but didn't get the cam chain tensioner. Also since I asked this question, I read at least 2 CCT's have failed. I'm up to 75,000 miles now, and just had valves checked at Alf England Motorcycles (they are the guys that stripped Nick Sanders' Tenere). Valve clearances were ok (2 exhausts just a tad tight, as they were at the last check, but not enough to worry about), and I asked about the CCT noise. Normal they said... which is absolutely true.

Now I'm thinking I need to get the new version of the CCT and install myself. The next leg of this trip is going to be back into some more remote areas, eastern Europe and Iran for starters, I don't need the CCT shitting itself there thankyou very much.

Is there a list somewhere of the parts I should order?

 

[Mzee]

My vote is not to fix what isn't broken. In fact, if the valves are still within spec, even if at the limits of spec, leave them alone too.

- Mark

In which case you are rubbishing the old adage "prevention is better than cure"?

 

[summitboy]

If you guys seriously think you need to change gears and chains at 20K your crazy. Your doing nothing more than throwing money to the wind. You are also doing nothing but damage to Yamaha's reputation on this motor. I can see maybe changing out a tensioner that supersedes an older version but chains and cams, cmon. I've seen/built some of their R1/Apex motors at 400HP going 25k on the snow turning a 174" 3" track without ever ever changing a cam chain. Same motor cut in half. Gears ? Please. Nonsense in my opinion ! Haven't some of the S10's gone 200,000k ? Were theses chain replaced ?

 

[longride]

Do you NEED to change your cam chain at 20K? Not a chance. Can you change it? Certainly. You could have a crankpin on up motor rebuild too. I doubt it is necessary, but you COULD!

 

[Old Git Ray]

My bike has 48k miles on it now and I did the (first !) valve check at 46k (all in spec).

Now the problem (if that is the correct word) of the CCT has raised it's head I have decided to change it for the 14. On purchasing the parts, I asked my dealer (who is also a Yamaha dirt bike racer) if I should change the chain. He replied that I should. Having done the valve check myself and knowing what was involved, he said I may well just do the chain as the cost is minimal although the work is around double.

Alf England did the same to Nick sanders' bike just because the chain was cheap and the bike opened up.

Has anyone that has changed the chain compared and possibly photographed the chain and sprockes, old to new, for wear and strech to assess it ??

I have decided to document/photograph the whole process and stick it in a thread for possible 'sticky'ing.

I have to thank the many mechanically active members on this forum who have given me the technical info/data to tackle this. ::008::

 

[EricV]

Ray - I would suggest you do the CCT and not worry about the chain until the next valve adjustment. You'll have it torn into more then. The CCT swap is less invasive, especially if you just R&R it, rather than following the FSM procedure for cam removal. The chain is not a weak point, IMHO, and will easily go well past 100k. Changing it at your next valve adjustment is still overkill.

There is no spec for wear or stretch on the cam chain. I went over this issue with Yamaha a bit, due to a warranty repair for a failed CCT. They didn't want to cover the chain, as wear is not a covered item, but they couldn't define the difference between wear and excessive wear with any hard numbers. In the end, it appears they are paying for a new chain, but it's not completely settled yet.

 

[dcstrom]

Ray, I had my new '14 tensioner installed at Yamaha Motor France - the tech there said I should replace the cam chain "when I get a chance" - which I took to mean the next valve check. Given that I was at 76,000 miles then, it will be 100,000 when I change the cam chain. Hopefully no problems till then, but no reason to think there will be, engine is very quiet now with the new tensioner.

 

[Old Git Ray]

Ray - I would suggest you do the CCT and not worry about the chain until the next valve adjustment. You'll have it torn into more then. The CCT swap is less invasive, especially if you just R&R it, rather than following the FSM procedure for cam removal. The chain is not a weak point, IMHO, and will easily go well past 100k. Changing it at your next valve adjustment is still overkill.

There is no spec for wear or stretch on the cam chain. I went over this issue with Yamaha a bit, due to a warranty repair for a failed CCT. They didn't want to cover the chain, as wear is not a covered item, but they couldn't define the difference between wear and excessive wear with any hard numbers. In the end, it appears they are paying for a new chain, but it's not completely settled yet.

Thanks for the advice Eric but the chain is paid for and on its way so I am just going to fit it anyway. Retirement gives me lots of time to play and I quite like dabbling - I just wish I was good at it :-[

Ray, I had my new '14 tensioner installed at Yamaha Motor France - the tech there said I should replace the cam chain "when I get a chance" - which I took to mean the next valve check. Given that I was at 76,000 miles then, it will be 100,000 when I change the cam chain. Hopefully no problems till then, but no reason to think there will be, engine is very quiet now with the new tensioner.

Hi Trevor, Iv'e been following you progress on FB. I am just a lot jelous.
My bike is seriously noisy and I cannot afford a major catastrophe, although I do appreciate that detonation is extremely unlikely, I am probably on my last bike so I want to look after it - mechanically anyway. :-\

 

[greg the pole]

Can someone clarify something for me...

The CCT is weak point in my very limited opinion and knowledge base. A couple of cct's have given up the ghost, and in turn bent valves.
the stock CCT is noisy at startup before oil reaches it, and then it's good to go, but I still don't trust it. So I've replaced mine with a manual CCT. Cheap, and easy to adjust/service.

Now, why change the chain? If it streches, the OEM cct will take up the slack, and the manual CCT (me ::025:, will give it a turn or two, and that's that. What's the likely hood of the chain actually snapping? So if you're replacing the chain, are you going to swap the two cam sprockets, and bottom sprocket as well?

Maybe if you bagged the bike, and rode it like a complete muppet for 200xxx km, then yes maybe, but I think this motor is overbuilt, and so is the chain.

I'm hard on my bike (throttle wise, maintanance schedule is followed over and above recommended), and 5 of the 8 valves were tight on my motor ( 4 ex., one intake) at 42km.
My buddy who's slightly easier on his, decided to hold off on the valve check till 59km, and 2 out of 8 were tight (both exhausts).

So for the guys that check their valves and are within spec.. why bother with the chain, and sprockets? If we second guess the yamaha boffins that eat, breathe and crap Yamaha...we would be changing everything on this bike.

I for one will only be changing the oem cct, and clutch basket (2014), and flashing the ecu, and the exhaust is gone, and the stock bars and the big floppy turn signals.....damn.

Curious minds want to know...

 

[Koinz]

The chain will last many thousands of miles, but as they wear they begin to bind at the connection points of each of the links making it more difficult to straighten as it comes off the gears. The gears will also wear and the chain wont seat properly. Since they're always bathed in oil, it's not as drastic as a chain drive bike and associated sprockets, but the same thing happens. You'll probably hear them get really noisy with clicking sounds as the links try to steaighten. My sons trx450 race quad had a worn chain and you can really hear it. He caught just in time.