A costly mistake
I have a 2003 suzuki Bandit 600. I brought it onto the lawn to clean it a while ago and as I walked away, it fell over. I picked it up and was pissed to find both signal lights broken. No big deal I had a spare so I replaced one and taped up the other. Well, a few days later, I was going to go for a ride. When I went to start it, it made some noise on the top end that I had never heard before and never want to hear again. Anyway, it wouldn't start so I pulled the valve cover off and found 2 broken rocker arms. I looked it over really close and come to the conclusion that the last time I had the valve cover off, one of the 2 dowel pins that line up the cover had fallen out and must have just sat there on top off the head. When the bike fell over, the pin fell into the timing chain and got between the chain and the bottom gear. It jumped the timing out enough to have the piston slap the valves and brake off the rocker arms. Luck for me it didn't bend the valves, and the bottom gear is fine.
Still a costly screw up on my part for not paying attention putting the cover on.
A friend has the 1200 bandit and he checked his cover and foung one of the pins was ready to fall out as soon as he lifted the cover.
Gear Driven Cams
You know, I think that's exactly what happened to my wife's Ninja 500 when it had it's major service a year and a half ago. After the engine siezed with less than 200km on it after the service, we took it in, and it too had eaten a piece of metal into the timing chain. We weren't so lucky, it bent all the valves before siezing.
We thought the mashed piece of metal might have been a valve clip (still have the piece) but the shop said it wasn't. Not surprising, given that they were the ones who did the valve adjustment.
In any case, it's all fixed now, so I suspect yours will be fixable too. Have your valves checked, or look for scoring on the pistons where the valves may have impacted. Don't want to replace the broken rocker arms, get it all back together, and *then* discover your valves are bent too.
It's fixed now, we pulled the engine out and shipped down to River City Cycle in Kamloops. they found the pin in the bottom. A leak down test showed no bent valves but they suggested pulling off the head and having a closer look, since the engine was sitting on the bench anyway. For the price of a head gasket, I said go for it. Like you said, don't want to find out theres more problems later. I got it back in the bike, just waiting for a new front sprocket and we're back on the road (tomorrow). It's been a while so I had to ride my wife's Shadow.
sweet glad to hear your bike is back up and running soon... dont forget to take it easy on that new head gasket! (break in period)