Cam chain replacement - is that normal?

[Knaapie]

Ok guys and girls, got a question. I've got an 2003 SV650S with about 57.000 km (36.000 miles) on it. Bought it in 2003 and did about 7-8 trackdays a year with it since 2005.

Last summer when picking up the bike from the 30.000 miles service, my dealer pointed out to me that the cam chains (especially the front one) would have to be replaced on short notice (as in: next service interval). He told me the wear was caused by doing track days and a more "sporty" riding style. Ok, if he says so. When listening to the bike, I have to admit it does make a pretty hard rattling noise, coming from the front cillinder (much more rattling noise than other pointy SV's). The rattling occurs both when riding and when running idle.

But when I was talking to some other technically skilled SV riders, they could'nt imagine the cam chains already need to be replaced. One of them has an curvy SV with more than 56.000 miles on it, but didn't do track days with it. So now I'm beginning to doubt the advice/ information the mechanic has given me. It's a pretty expensive repair :mad:, so I want to be as sure as possible.

So now my questions are:
- Is it possible that the cam chains need to be replaced at 36.000 miles? I can imagine that certain riding actions makes the chain wear out faster (traffic light sprints, wheelies, cracking the throttle very often), but I'm not in to all of these things.

- Is there a way to check the length of the cam chain and compare it to a new one or service limits? I wasn't able to find any cam chain service limits in the service manual. At the moment it's the opinion of the mechanic without any "hard" evidence.

- Could it be just the tensioner? Unfortunately I'm not that technically skilled to try certain things myself, especially when the engine is involved.

I already did a search on cam chain problems, but haven't found what I was looking for. So hopefully someone over here can help me out!

Thanks!!! :thumbsup:

[yorkie_chris]

36k isn't really much for an SV motor. IIRC haynes has a length between pins limit for camchain, but it's kinda strange you can measure one that's totally bolloksed and it'll be in limit... or get one that measures stretched to buggery, but runs alright and quiet. That's not on SV engine though, I've never heard of an SV needing it!

However, I'd ask Sid Squid about it.

[injury_ian]

So now my questions are:
- Is it possible that the cam chains need to be replaced at 36.000 miles? I can imagine that certain riding actions makes the chain wear out faster (traffic light sprints, wheelies, cracking the throttle very often), but I'm in to all of these things.


SV's are notorious for not liking the wheelies.

Maybe not chain, maybe small / big end bearings??

[northwind]

Surprises me too... If it's had a bad tensioner then the slap would maybe wear the guides, but chain stretch, I'd be a bit skeptical. I don't know what the runouts are unfortunately but accessing the chain is very easy if you can find it. Did he diagnose it just based on noise?

[Dangerous Dave]

36.000 miles
Way to early for a new chain.

[yorkie_chris]

Yours on stock camchains Dave? What mileage you replace them at?

[Dangerous Dave]

Recently, around 98000 miles, not entirely sure it was needed to be done but I had the engine apart so took the opportunity.

[yorkie_chris]

Oh right. sprocket for front chain being part of crank is a bit of a bugger though. Or is billet crank different?

[Dangerous Dave]

Same as OEM, and 'a bit of bugger' is an underestimate!!!

[Knaapie]

SV's are notorious for not liking the wheelies.

Maybe not chain, maybe small / big end bearings??
Sorry, made a typo. :o

I'm haven't wheelied with the thing since I got it. Rarely do traffic light sprints and I'm not really a rider how cracks the throttle often. I can imagine this kind of riding has an impact on the cam chains, because the power comes on at once. Or is this complete BS? :)

[Knaapie]

Surprises me too... If it's had a bad tensioner then the slap would maybe wear the guides, but chain stretch, I'd be a bit skeptical. I don't know what the runouts are unfortunately but accessing the chain is very easy if you can find it. Did he diagnose it just based on noise?
The 30.000 service includes checking the valves. I can imagine that they did a quick measure on the cam chains, but I don't think that's in the service schematics. He didn't really explained how he came to the conclusion, but as far as I understood, he based it mostly on the noise, yes.

I'll give him a call this week and ask him how he exactly determined it. I'll also try to get an answer from Suzuki. Hopefully they'll have some valuable input for this.

[Knaapie]

Way to early for a new chain.
That's something I've been hearing too many times now... :-?

The fact that I do track days with it as well doesn't really affect the wear of the cam chains?

[northwind]

Maybe a little, but they're not really under huge stress in the grand scheme of things.

[Sudoxe]

It's not normal, but not entirely out of reason.

On my speed triple engine (a second hand one, supposedly with ~16k on it) I had to replace the cam chain at about 25kish, as it had stretched.

If your handy with a spanner, I would check it out myself.

This would involve removing the cam covers and checking your cam chain tensioners are working, and then the chain is becoming tensioned properly.

If you wanted, you could remove the cam chains and measure them if you can find the length of the OEM ones.

WARNING: Dont go removing the cam chain tensioners, or cam chains unless you are happy with setting up the timing on the engine, as things can slip when you remove the tensioners.

Also, don't take my advise, as im a mechanical numpty and murder anything mechanical i touch.

Dan

[Knaapie]

Mmmm, ok. So what could the cause of the increasing rattling sound then? I do have the idea that the noise is louder when I just start it up in the morning, than when I come home after a ride.

[Sudoxe]

Mmmm, ok. So what could the cause of the increasing rattling sound then? I do have the idea that the noise is louder when I just start it up in the morning, than when I come home after a ride.

It's quite common for the cam chain tensioner to become stuck. I would check that first.

Dan

[Knaapie]

Grrr, still would need a spanner for that...

[yorkie_chris]

The k3 isn't known for weak tensioners though

[Sudoxe]

The k3 isn't known for weak tensioners though

No, but realistically in this setup, we have 2 parts which can conceivably brake or wear*:
The cam chain
The chain tensioner

Now, it costs nothing to check that the cam chain is working, and that the cam chain is tensioned correctly. Or you can replace the cam chains at a cost of £94.92 (http://motorcycleproducts.co.uk/catalogue/suzuki-sv650-sxsk13-199904-cam-chain-p-45810.html) and still potentially be stuck with a broken tensioner.

*Sure, the teeth of the cams or crank could wear or brake the plastic guide could wear, etc, etc But lets be sensible, use occam's razor (http://en.wikipedia.org/wiki/Occam%27s_razor) lets start with the normal stuff.

Still, im no expert on engines, i've just done this several times.

Dan

[yorkie_chris]

Indeed nothing wrong with checking.

However did this just start all of a sudden, a shim not being seated in valve retainer will cause a bad rattle from front pot.