|Yesterday, 03:45 AM||#1|
Joined: Aug 2010
KTM 690 Enduro Rebuild
Last weekend, my 2008 690 died 600km away from home. Quite the hassle to get it back... Well, yesterday, I picked her up and brought her home with a van. The rest of the evening was spent taking the engine apart.
The damages weren't quite what I was expecting. The bike has 29400km on the clock, and would've have had a valve inspection coming up real soon, such a shame the issue emerged before that.
Here's a couple of photos, I'll add some once I inspect individual components closer.
Yup, the shim was knocked out from the second intake valve.
It seems like the valve spring retainer and collet split right in half, causing the valve spring to jump up and jam the intake rocker and allowing one intake valve to touch the piston. As the valve spring jammed the intake rocker, it caused damage to the camshaft. Of course it could have gone the other way around, difficult to tell, other than a "dent" on the cam lobe and as if it would have hit the rocker bearing really hard causing it to seize.
The bike has a evo 2 set, except for the akrapovic titanium header and has a Wings silencer. This set up has been on since 7500 km. The exhaust side of the head is completely fine, no skuffs or big marks on the rocker arm bearing or cam. If the rocker arm wasn't original from 2008, I'd leave the exhaust rocker be.
I'm planning on putting a new evo 2 cam back to the bike, but I'm not sure yet. I have the original cam that has 7500km on it on a shelf, but I noticed that a part number changed for it. Is it still usable? It looks brand new and has no signs of damage on it.
Here's a part list so far:
76236010044 Evo 2 Camshaft 75036061144 Rocker Arm exhaust 75036060144 Rocker Arm intake 75036030000 Intake valve 59036027000 Valve-stem sealing racing 75036028044 Valve Spring kit 60036033000 Valve Collet MK6 03 (2 pcs) 75030036000 Cylinder Head Gasket 75030035000 Cylinder Base Gasket
The cylinder head will be taken to a shop to machine the head and reseat the valves.
I may not have gone where I intended to go, but I think I have ended up where I needed to be. - Douglas Adams
KTM LC4 400 2002 - Military version
|Yesterday, 09:25 AM||#2|
lost in the 690 mega
Joined: Aug 2010
Location: Santa Maria, CA
Maybe it's just me, but anytime I've needed to replace ANY valve, I've always replaced ALL of the valves. At about $40 each, they aren't very expensive (compared to titanium valves or some of the aftermarket stainless valves.) Your machine shop cost will be the same either way so it makes sense to me to just make everything fresh now... at a minimum, throw some new rings on the piston and if the damage to the top of the piston is anything more than superficial, replace the piston too (I'd personally just replace it since there has been mechanical contact.) If it were my own bike, I'd replace the timing chain too, who knows what kind of load that thing saw if/when parts got lodged in the valve train. Yes, that all adds about $400-$450 in parts to your repair, but then you could forget about it for the next 29400km.
I can ride my bike with no handlebars, no handlebars, no handlebars - Jamie Laurie
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