Broken Valve Shim

[amkluttz]

I was taking off from a stop and decided to punch it.  I hit around 9500 RPM and then something went terribly wrong.  It almost sounded like the exhaust had come completely loose from the front of the motor and then horrible ticking.  I shut it off immediately and checked it over visually.  Ended up riding it home the 3-4 miles at very low RPM. 

I pulled the cover off the top and found my right intake valve missing a shim.  I found a small piece of the shim so I know it's broken but I can't find any more of it.  The bucket has some slight damage to it and the cam lobe is slightly chewed up on the sides from hitting the bucket.  The bucket still moves freely but I have not tried to compress it. 

The valve shims were changed back in June about 1300-1500 miles ago.  The bike then made a 4 hour interstate trip (about 250 miles), I was able to ride the Tail of the Dragon and the Cherohala Skyway (another 120+ miles), and then made the 4 hour trip back.

What is my next step?  Is there anyway to get a magnet down in to the cavern that is the cam chain and get the pieces out?  Is it time to pull the motor and tear it down?  Could my valves be bent?  What else could be wrong?  The cam chain seems tight and I didn't notice any problems with it.  I was able to turn the motor over by hand without any nasty noises.

Please help.  I have a little one on the way and if I can't get it fixed I doubt I will have the funds to fix it or for a new bike for a long while.  Pictures to come...

-Andy

[Cerberus73]

Well its safe to say that there will be a chunk or chunks of shim floating about somewhere in the crankcase of your motor.. you could get supremely lucky and get it out by dropping the sump(oil pan) cover and doing a flush through.. either way the top end of your motor will need work, new cam, new bucket, new shim... but could you be certain you got it all out? id hate to imagine what a chunk of shim getting stuck in your transmission would do to the bike at 80mph or so.. it is probably safer, but more expensive cash wise and time wise to pull the motor and do a clean up and rebuild.. on the plus side you won't lock the bike up at 80mph and end up leaving your hide along 1/4 mile of road.. and can check to ensure that no other part has taken damage.. if you got the shims done professionally before you may have recourse to claim for the damages if it was only a short while ago.

[The_Paragon]

Sounds like you got lucky!

http://gstwins.com/gsboard/index.php?topic=67732.0

Drop the oil pan, the rest of the shim chunks should be down there. The cam chain channel is kind of seperate from the rest of the engine. By the way it looks when I took mine apart I dont think shim chunks would make it too far elsewhere. Give the cam chain a really good look over to see that there isnt a bent link anywhere from a peice of shim getting between it and the gear on the crank. Check the gear on the crank over well. Mine had a broken tooth. If your cam chain didn't break and the cam timing is still on I doubt the valves are bent.

Sounds like you'll need a new bucket, shim, and cam shaft.

Do you remember if it was an aftermarket shim or a Suzuki shim? The shim I broke* was a K&L shim.

*Its still up in the air whether the shim broke first, or if the bucket stuck and the cam lobe kicked the shim out, then it got eaten by the crank gear and cam chain.

[amkluttz]

So far the cam chain looks okay from just spinning the motor over by hand.  It chewed the cam but only chewed it on the edges of the cam lobe.  The lobe looks to be in perfect condition where it hits the shim.  I'm hoping tomorrow night I can pull the cover back off and get some pictures.  I'm going to drain the oil and pull the oil pan cover hopefully at the same time and see what's going on down there. Would it help at all to pull the right side clutch cover as well?

If there is any way to get this bike running again without having to pull the motor that would be amazing.  It's about prime riding time around here and it would be great to get another ride in before the end of the year but not at the expense of losing the motor.  I'm crossing my fingers.

Thanks,
-Andy

[Cerberus73]

Cant see what good pulling the clutch cover would do, as the shim bits will be in the crankcase itself.. pulling the clutch cover won't give you access to that area of the motor. your best bet is to drop the sump cover (oil pan cover) drain the oil.. check the oil for metal bits, and a metallic sheen (could point to scarier stuff inside the motor) hopefully you will find the missing bit or bits of shim there.. the main thing is once you have gathered all the shim bits, that it adds up to a complete shim.. if not then you will still have a chunk rattling about somewhere in your motor. thoroughly check the camchain for damage, check the cam sprockets.. and anything else you think the shrapnel ricochet off. sure i know you just want to get out and ride, but believe me I've blown up a GS before.. cam chain went, valves met pistons at about 70mph.. i was lucky i pulled the clutch in quickly. result one motor blown beyond economical repair.

[amkluttz]

It's been a while since I posted about this.  My wife and I have been travelling a lot lately and I haven't had time to work on the bike.  I'm pretty certain the motor will have to be pulled and some level of rebuild completed.  I was hoping that I would find two large chunks of valve shim and nothing shimmery in the oil but that isn't the case.  Does anyone have any idea how deep I am going to have to go in to this assuming nothing major is broken and I can re-use most of my parts.

The initial oil drain was ran through a coffee filter and it didn't appear there was any metal in it.


Dropped the oil pan and found a bunch of black gasket maker.


Once I pulled the oil pan this is what came out.  I didn't pull the oil filter so some of this flowed from there I'm sure.  Shimmery!


The two large chunks came out of the oil pan.  The smaller chunk was in the top of the motor next to the valve bucket.




A few of the cam lobe.  I'm assuming I need a new camshaft.  What harm could come from filing the edges of the lobe smooth and using it as-is?






Is the damage worth fixing?  I found an entire head from a F model on ebay for around $300 and an entire dyno tested '04 motor with 6500 miles for $800.  There are also two local entire bikes (unknown mileage) for around $700 with title issues. Parting my bike out probably wouldn't get me very far monetarily.  I just want to take a look at all of my options.