Originally Posted by motodirtlover
That chain was a relatively new "parts unlimited" o-ring off-road chain. It had about 200 miles on it when Swingset procured the machine.I've had hit and miss success with those. For $70, they generally work well, but I do "over-lube" chains after I wash the bike. Some last a lot longer than others. If you want a super long-lasting chain, buy either a Regina (best), RK , or DID.
As far as the cam, when Holycaveman had it apart last year rebuilding it, it looked perfect. No grooves. The engine ice coolant may have contributed to the early wear (due to the silica content), but that is unknown. There haven't been that many miles since the rebuild. (I'd guess 2-3K).
I agree with Swingset though, the KTM RFS cam is a known sore spot for wear. There is an aftermarket cam guy that makes one with an extra-hardened sleeve at the wear point by the seal.
RFS bikes can be a little service-prone when you ride them alot, but they will run a LONG time if you take care of them.
I love those things.
Thanks for the info, I suspected the chain puked too early. I've only put about 200 miles on it, and it's been well lubed the whole time..most of my miles were offroad.
I have looked into sleeving the cam, but it looks like it's a little too skinny for ready-sleeves and someone machining one for me would likely be the same cost as a new cam, so it's a wash....same with a grind and coating, you're talking $150 at least in shop time for that, and hell there's a new cam....tho it may last longer than an OEM. Not sure. I don't know what's involved in replacement, I'm hoping I don't have to break the cam chain and pull the motor, I haven't found a thread detailing its replacement yet but I'm sure someone knows.
I lucked out and found a NOS decompression cable on fleabay for $10 shipped, so I'm gold there and the CS seal kit/washer is en route. I'll probably put a Primary Drive chain kit on, they've been really good on both bikes I tried them on, for the money I think they're the best deal going on chains. I tend to take good care of my chains, and they've lasted a long time. I imagine this one probably was a defect or a case of a pin/roller not getting any lube from the factory and it burned it up and made it brittle.
I'm loving the bike when it's healthy tho, I can't wait to take it out to the desert next year...it's going to be a blast on those fast open single tracks.