Camchain tension

[breakwellmz]

Hi.Is there manual adjustment of the camchain tension on a Mastif?I can find no reference to it in the maintainance schedule in the handbook.I have noticed lately a "camchain type noise" for a few seconds after a cold startup-to me suggesting an oil pressure reliant tension.I have done an oilchange recently.Any advice appreciated.Cheers.

[rodge70]

join the club,mine's been doing that from new,after a few mins riding it goes away still a bit worrying though as bike is just 2 years old.
think i mentioned this to grahams at service but he did'nt think it was a problem,off for last warranty service very soon so will pick his brains then. may be over your way this sat if a cuppa is going ,but not sure where you are,rodge

[Anders]

It is an automatic spring and ratchet type tensioner, oil pressure is not part of the equation in this case.

[breakwellmz]

Thankyou both.Yes Rog,do pop over.It`ll give me an excuse to have a break from doing my kitchen/chores/tidying garage!I`ll text you.Cheers.

[Bill Jurgenson]

Nonetheless, if the chain seems to getting noisy, you should have a look at the tensioner. There are issues about the Borg-Warner-type silent chain and longevity. They have been know to tear and that seems to have an issue with a particular batch of OEM chains. Basically, a silent chain is not very strong and if forced, it will lengthen. When this happens, the tensioner readjusts accordingly and the whole starts afresh until there is nothing to lengthen: tear!
Since this particular chain is used in several Yamahas including the R6, it can be very random. If the chain does tear, it will be very expensive, meaning some or all valves and valve guides will need to be replaced. A broken rockerarm or two is also very possible. I know this from lots of personal experience with racing engines. One reason why such engine often use a rollerchain instead and not just mine as the Slipstream kit shows. For standard usage and stock engines, don't worry, the silent chain is more than good enuf - apart from the issues with certian individual chains.

If you want to check, do the following:
1) remove the central large spring cap screw(19mm box wrench) on the back left of the cylinder and remove the coil spring.
2) unscrew the tensioner itself - 2 M6 bolts, either 10mm wrench or 5mm Allenhead.
3) remove carefully in order to not damage the gasket which can used over and over again if it is in one piece.

Now check how far the tensioner plunger is extended: measure (or count the grooves) the visible extension first, then with a narrow phillips screwdriver push it out from the sring end to see how much more extension is possible. Roughly half to twothirds is OK. More is pushing it. Less would be like new!

To replace the unit, lift the rachet stop and push the plunger back all the way, then screw the tensioner back into it place, then replace the spring ( you will hear the plunger rachet forwards) and and cap screw. Don't worry about torques here, just tighten firmly (not brutally!)

If you do this, you will know decisively how the thing works and what to expect.There is no black magic or occult knowledge involved.