find lost valve shim?

[canucklehead]

2007 450 SX-F. cam went out of time (guessing hydraulic chain tensioner failed, as I hear they are notorious for failure).

exhaust valve spring retainer broke in half, both collets came out and the valve guide broke off a chunk. other top end damage, but I won't tell you my sob story for fear you'll hack your wrist.

I found what looks like the mushed up collets, the two halfs of the broken retainer (thanks KTM....I can't just buy a new retainer, I have to buy complete valve spring assembly ). When I took pipe off, I found a chunk of the valve guide rattling around inside, and I also found a small chunk of valve guide on top of piston. I have NOT found the valve shim. I think i have everything else.

I have engine out. This was the exhaust valve, nearest the timing chain. I thought shim might fall down through the valve chain area. I thought the shim might stick on the magneto (once on my 525 KTM, the decompression lever broke and I found the broken chunk stuck to the magneto). Magneto cover is off, and nothing on the magneto. I have drained oil and strained it, can't find the shim. Searched with a light, magnet (where I can fit it), etc.... I shake engine but can't hear any rattle.

Is it possible it blew out exhaust as all this damage happened? Any other nook/cranny it might stick in down below? I don't want to re-assemble and have that hardened steel shim grenade around.

Can I put in oil plug and add some solvent, then shake it around and drain it? Would solvent hurt anything?

Oh yeah, I am trying to remove oil pump to see if that shows me anything, but it seems to be very sticky to pull out. Am I missing something on that?

Do I need to remove the clutch cover to fish some more?

Any suggestions?

THANKS

[bajadog]

Check out this guy's horror story.

Might post on his thread and see if anyone answers.

Sorry I can't help much, but I still have not gone to the
DOHC cam KTMs yet.

http://ktmtalk.com/index.php?showtop...ain++tensioner

[canucklehead]

thanks for that link. that site appears to be down. hope they can fix it cuz I'd be curious to read the story.

[bajadog]

It works now. PMed you too.

[canucklehead]

FINALLY foud it. when I first removed head, engine was still on bike ( I only wanted to touch the top end). DOH! and I wasn't sure what I'd find or that the valve would be broken. It wasn't until I saw broken spring retainer that I wondered where I'd find the shim.

My son was doing a F350 axle swap on his F250 TTB. The 250 axle was on the other end of my shop, nowhere near where I worked on the bike. I was pounding off the hub axle spindle to salvage parts. I saw a shim on the floor and thought it fell out of the axle. It was definitely the valve shim, fits perfect with a couple of little nicks in it, probably from rattling around.

it must have been on my shop floor and kicked around. must have fallen out when I originally pulled the head, while motor was still mounted. what a relief to not have to split cases!! but I'll still pull the flywheel rotor to see if any other little pieces of metal got hidden in any crevices. then the re-assembly starts.

[bajadog]

Good to hear you found it.

I've had some crazy "how the hell" stories like that before,
my last one was an oil pump c-clip that jumped up onto my
workbench all the way across a 3 car garage.