Long story short: I drag raced a friend, got a little too close to red line, probably low on oil. The rest of the (brief) ride home, the engine made some pretty rough knocking sounds, but it didn't seize up or start spewing fluids.

Video of it running here:
http://youtu.be/1hXR3a3IgxA

Really bad timing. I'm moving this week to an apartment with no garage, so I can start grad school, which means I will have no time to work on it. Grrrrrrrrrrrr

That kinda just sounds like an exhaust leak... See if your header bolts are loose.

- Bboy

+1 sounds like the header bolts worked themselves loose, creating an exhaust leak. Mine did that at 60mph down a back road and I about shaZam! bricks. Tightened em back and up and problem solved.

after re-tightening them, pour salt water over the bolts so they never budge again 

.... juuuuust kidding, they make high temp thread lock for that

did you win at least?

If only it was so simple. I checked  the exhaust bolts, and they are tight. Maybe you can't hear it in the video, but there is a distinct metal-on-metal clanking that makes me think something is broken. The engine has been leaking around the cylinder head for a while now, so its probably due for a rebuild anyway.

Did I win? More or less. My friend was driving his BMW autocross car, and I had him until I got around 80-90mph, at which point I think the damage was done. In his words: "That wheelie was awesome!"

Lesson here.... dont drag race.. a GS aint a Busa! If your head gasket is blown.. you may get away with just a top end rebuild.. as long as you are sure your bottom end is fine, but considering GS balancer shafts can be weak point in a neglected motor or one thats gone low on oil.. id be careful.. for all the price difference when it comes to full or top end only gasket kits. id pull the motor apart if you suspect there is deeper damage, just to check every things in spec and to ease your mind.. depending on how comfortable you are with performing a complete motor rebuild. if you need to pay a mechanic.. it may be cheaper just to source a good used low mileage motor. and get the valves checked and a full service on it.

QuoteLesson here.... dont drag race.. a GS aint a Busa!

There is a lesson to be learned here, however its not don't drag race a gs. Personally I ride mine like its stolen, I wont race a cager but thats a personal choice. If your GS don't bring a smile to your face at least a few times while your riding your doing it wrong.

For the OP pull your starter clutch cover, and your rotor. Inspect your starter clutch, typically it don't sounds like that but since it was happing just with turning the motor with the starter who knows 

If you dont find any thing there inspect your valves and take a look in your plug holes to see if you could tell any thing.

Its possible that one of your valves broke due to high revs

Reviving this thread because I finally have some time to look at my engine.

I drained my oil and it looked clean. A bit dark, but I didn't see any particles. At this point I should have pulled the oil pan to check more thoroughly, but hey, hindsight, right?

I then pulled the engine out of the frame and checked my valves. Pretty sure I found the problem. There is nasty gouge in the engine wall next to the cam lobe, along with some heavy marks in the lobe itself. There is also a piece of the shim next to the bucket. I'm not sure what happened, but somehow the shim got out of the bucket and shattered, not necessarily in that order. Looks like I'll need a new cam at least.

Could be worse. Top end is better than bottom end.

Also just noticed that the marks from the top photo actually go all the way through the head, and can be seen on the outside:

So apparently the shim came out with a LOT of force.
I rode about a mile to get home after the shim got thrown, and there doesn't seem to be any leakage around the crack. A friend suggested looking for someone to weld it, but I think it would be cheaper to just replace the head.

Pulled the head and cylinder (stuck together), and the pistons looks pretty crispy. What do these engines typically look like?



Side note: if you pull your engine apart, be sure to clean the grunge around the seams. I wasn't expecting the cylinder to come up with the head, and some gunk fell into the crank case.

Cleaned up the pistons and replaced the gaskets, bucket, and cam.
After talking to people who actually know about these things, I was surprised to find that the prevailing advice was to use JB Weld to seal up the crack in the head. I used a dremel to clean it up and form a groove, then filled it with JB Weld.
I put everything back together and got the engine back in the frame. All I need now is new shims to get the clearance in spec and a battery.

Nice work, engine work is always fun!!

I wish I had more time to tinker around with motors.

Quote from: SmithvilleFlats on January 03, 2015, 02:16:50 PM
Pulled the head and cylinder (stuck together), and the pistons looks pretty crispy. What do these engines typically look like?

picture

Side note: if you pull your engine apart, be sure to clean the grunge around the seams. I wasn't expecting the cylinder to come up with the head, and some gunk fell into the crank case.

my 05 looked worse then that on the crispy scale! you're good! lol

Quote from: SmithvilleFlats on January 18, 2015, 07:41:57 PM
what shims do you need? smaller or bigger? I have a few, as do some other forum members. if you can get a size, its possible one of us could mail em.
Cleaned up the pistons and replaced the gaskets, bucket, and cam.
After talking to people who actually know about these things, I was surprised to find that the prevailing advice was to use JB Weld to seal up the crack in the head. I used a dremel to clean it up and form a groove, then filled it with JB Weld.
I put everything back together and got the engine back in the frame. All I need now is new shims to get the clearance in spec and a battery.

You might want to take a look at your shims.  There are some aftermarket shims circulating that have been known to shatter, K&L brand I believe.  They have a different font for the number on the shim than the OEM shims.  There is a thread about it if you search.  Post back when you find out what kind of shims you have.

Quote from: jacob92icu on January 18, 2015, 09:16:26 PM
Nice work, engine work is always fun!!

I wish I had more time to tinker around with motors.

Agreed! I had some time off, and this was pretty much my vacation.

Quote from: bombsquad83 on January 20, 2015, 02:50:11 PM
You might want to take a look at your shims.  There are some aftermarket shims circulating that have been known to shatter, K&L brand I believe.  They have a different font for the number on the shim than the OEM shims.  There is a thread about it if you search.  Post back when you find out what kind of shims you have.

Yes, the shim that shattered was from K&L. I've had some contact with them, but haven't had time to fill out all the paperwork yet.