blistovmhz

2010 FE450. Got teh bike with 18h on it. No idea on hours now, but it's approaching 10,000km and I figure I should probably do some service.
Nothing wrong. No indication or hint of anything out of spec. I'm sure the valves have gotta be at least a little tight by now, so I was going to tear it down and at least do valve shims, but figure if I'm in there, and I'm nearing 10k, it's probably time to do a few other things?
I've heard lots of guys say 10k on a piston is fine. Others say that's probably the time to be changing it before it explodes.
What's a decent piston kit, and what else should I be doing while i'm into it?

Taffy

the piston will tell you when it's had enough; it will be like riding a smoke machine. it is the only true 'wearing (friction)' part in the engine.

Taffy

blistovmhz

That's what I'd always figured, but I've heard guys say the piston, assuming the rings survive long enough, will just explode, taking out the entire motor, seemingly at random (most guys seem to suggest 10,000km is sorta the upper limit).
But that said, I've never seen any pictures/evidence .

Mine runs absolutely mint. Starter feels perhaps a little chuggy, which I'd assume would be the valves being a bit on the tight side, but it always starts and still makes loads of torque, and zero smoke whatsoever.

Taffy

I don't know where the story of a fraggging piston comes from. no9t in this community anyway

Taffy

blistovmhz

Well then, perhaps that's good news. I'm insanely busy lately and absolutely don't want to be wrenching when I could be riding (I love wrenching, but running 3 companies at this point, I just wanna be able to go for a rip at the end of the day, and there are no competent shops I could trust to even change a tire for me here ).
I'll just do the valves today and cross my fingers. Thanks man.

*edit*
Huh. Popped it apart, and valves are all a touch loose. I've never seen this happen in any other vehicle, but seen a couple posts here suggesting this is just how the Bergs do. Is this normal?
I think clearances are supposed to be e/i 0.12-0.17/0.1-0.15? I'm just shy of e0.02 and around i/0.15. Should I just leave it or does it loosen further?

Botje

FWIW mine is now at 11K km and the engine has never been opened except for checking valve clearance two times. Enduro, supermoto use, no races.

If it is wearing towards more clearance that means the mechanism actuating the valves is wearing a bit faster than the valves/seats are recessing? You could take a look at the rocker shafts and rockers+rollers themselves. Also check if the shims are OK.
KTM provided an upgraded model of the rocker shafts which distribute the oil a tad better.
So I would check those parts just to be sure. But I'm pretty sure there is nothing wrong with them.
On my engine the original shafts are fretting a little in the cylinder head but no issues so far.

Rocker arm shaft upgrade

pegscraper

Not a 450 but I have a 2010 570 currently at 13600m and approaching 500 hours and it runs fine with no smoke whatsoever from cold to hot. Apart from regular 15hr oil/filter changes and screen cleans (OK it went 20 hours a couple of times) the only engine maintenance has been checking/adjusting the valve clearances, although the second time they were still in spec and a few plug changes. I fitted a DJH camchain tensioner very early on in it's life as the OEM hydraulic item was giving problems. I've also been running OAT coolant for the last 10k miles or so. I've no plans to tear down the engine to check wear on the piston or anything else for that matter, just keep an eye/ear out for anything unusual, leaks, noises, smells, vibrations etc and take it from there. I don't really worry about catastrophic component failure of any kind. This is with purely leisure riding and not competition use which no doubt would dictate a more rigorous maintenance regime.