Cam Chain Tensioners etc.. (for a change)

[andrewsmith]

I know this will have been covered on the org more than once.
But here goes,

The front cam chain/ tensioner has started to make a damm sight more noise than usual (mines always been a bit rattly).
The rattle is at Idle revs (circa 1500 rpm) and at between 5-6k rpm.

The rattle is also intermittent it seems to be every other time its running.


Any suggestions for the cause/ remedies.

Thanks in advance
Andy

[Nobbylad]

What year is it and what makes you think it's the tensioner?

[andrewsmith]

Curvy 2000 model

The noise has been there ever since I've got the bike, but it now seems to be getting very loud and seems to be coming from roughly where the tensioner is (Top of the cylinder barrel)

[Nobbylad]

Well if you think it's the tensioner itself and a pointy one will fit, I have one from a K5 if you want it. I bought a new one as the front cylinder was rattling a little, but it turned out that it needed a new cam chain.

[andrewsmith]

I'm going to have a lookski in the front and see whats going on.
As it was relatively quiet this morning going to work. Now time to annoy my mate for a hand and reignite his loathe of Suzuki CCT's

Nobby, whats the work involved in doing the chain? (just in case it is that)

[Nobbylad]

Assuming the curvy is the same as the pointy:-

Head, cylinder and alternator cover gaskets, a suitable tool to remove the alternator (M20, fine pitch bolt), lots of patience, something to store your woodruff key in safely and the new cam chain (obv).

The gaskets and chain set me back £149 and the bolt cost me a quid, so £150.

On mine we dropped the oil and coolant, took off the cams, cam chain tensioner, cylinder head and barrel and alternator. Put the new chain in, put everything back together, reset the timing, refill the oil and coolant.

Sounds easy and I could probably do it in a couple of hours if I was doing it again, however mine has taken the best part of 3 weeks, lots of tea, lots of help from YC both in person and on the phone.

Now it didn't help that we (I) lost the woodruff key and also, once I'd tightened everything back up, there was a slight oil leak on the cylinder head gasket. I re-torqued all the bolts up and as I did one of the bolts in the camchain tunnel...it snapped. So I had to take the head off and get the bolt out (was only finger tight...phew!). So now I need a new gasket, which was ordered next day delivery on Wednesday and is still not in stock!

[andrewsmith]

Cheers mate

The fundamentals of the motors are the same.
If its a chain it'll go to a mechanic to be done as I wouldn't want to have to strip the motor that far back (/don't have the skills and time to do it)

[Nobbylad]

I (bizarely) enjoyed it and it helped my understanding/improved my skills. I reckon for a dealer to do it, you're looking at 2-3hrs so I'd expect around £300-350 incl. parts.

[andrewsmith]

Originally Posted by Nobbylad

I (bizarely) enjoyed it and it helped my understanding/improved my skills. I reckon for a dealer to do it, you're looking at 2-3hrs so I'd expect around £300-350 incl. parts.

just spoke to a guy at work who used to run his own garage. He reckons that the tensioner needs reset, as that all hes ever done with them in the past.

I was working on about that. That would actually mean replacing the timing system is the same price as a major service

[Nobbylad]

OK - with the pointy, the tensioner is automatic in that it is a ratchet plunger with a spring. So you lift the ratchet, slide the plunger all the way in (so it's at it's shortest), fit it to the bike, insert the spring, then the bolt that pushes the spring in. As the spring compresses, it pushes the plunger onto the cam chain guide which then applies tension to the cam chain.

As the plunger is pushed forward, it clicks along the ratchet and can't retract back inside the tensioner housing. Therefore it is always tensioning the chain and will continue to move foward, under pressure from the spring if it needs to.

On the curvy's, I think the tensioner is tensioned manually by turning the top of it as it screws into the cam chain tensioner housing. Fitting a pointy tensioner is an improvement as I understand it to curvys as it takes the guesswork out of setting the tension 'just right' manually.

I'm sure someone else can confirm. My point around all of this is that my K5 rattled and required a new cam chain, I never made out yours needed a new cam chain, just that if it did, there's a bit of work involved.