Noisy Cam chain?

[yorkie_chris]

Glad you got sorted. Seems you seriously dodged a bullet with the skipped timing. That is rare, and generally causes immediate engine death.

Originally Posted by isutty5

The likely cause of premature wear: The mechanic stated the throttle bodies we're so out of sync he's never seen anything like it. Due to additional load on the rear cylinder, timing was under stress and thus causing wear on the chain.

That's rubbish. There's no way "load" on the cylinder wears the chain, it is simply not how they work. The camchain is driven off the crank.

My bet is on skipped oil changes, which would seem to be supported by the general state of neglect.

[SV650rules]

+ 1 for skipped oil and filter changes, as yorkie_chris rightly says problem with throttle bodies would not affect camchains which are only opening and closing valves, any roughness in running caused by throttle bodies more likely to affect little or big ends. Whatever you do don't use flushing oil as R1ffR4ff found out it can remove the ring of dirt sealing the oil into worn big ends and cause problems.

[Bibio]

not true about TB's and carb sync affecting cam chain noise. i have done a cppl of bikes that had cam chain slap that was cured by sync of TB's/carbs.

[isutty5]

I can assure you it wasn't skipped oil changes. I renew every 3k miles without a miss.

Only let down was the oil leak last year which had me running low for a short period. But that was almost a year ago.

Other than that it's been oil and filter change every 3k. Castrol power 1.

So if it's not oil change neglect or the TB sync issues. What else?

I'm genuinely interested in learning but no one seems to have an answer or at least tell me what the other person said is bull.

I do 12k/year on the engine, all year. She's been down a few times but nothing more than damaged plastics. She goes through rough weather, and I've done about one 6 inch wheelie.

I hadn't changed the air filter which was full of crap. So my bad there. She's had the well known wet front plug syndrome which was rectified with silicon and fender extender.

Other than the aforementioned, she's been an amazing bike and never skipped a beat before this cam chain issue. I had the curvy for 3 years before it was stolen and never had issues with that apart from the wet front plug.

[Craig380]

As one of the earlier posts said, it could well be an isolated component failure with the chain - even though SV engines are known for their reliability, one-off problems can happen.