Dropped bike and now it runs poorly

[fibersport]

As the title states, I went to stand the bike on the side stand and didn't realize it was pulled up, talk about a DUH! moment. Anyway, I noticed it was running a little odd, like the carbs were flooded or something and there was a slight bog. I didn't think too much about it since it was early morning and when it fell over, it was still running until I shut it off. It rode fine after a couple of miles. On my ride home, it seemed to still be acting up again. When I got home, it idled around 500 rpm, has a rattling sound from the timing belt area that goes away when I pull in the clutch and the exhaust smells maybe rich. Timing belts are new last year by the way. If I roll on the throttle, I can hear maybe some pinging and the exhaust note "could" be different than normal. I also noticed when I pulled it in the garage, having it on the center stand and idling, it would simply shut off, no sputtering or anything, as if the key were turned off. It does seem that it behaves a lot like it did last fall when I had a vacuum leak, the one hose between the throttle throats.

I feel real stupid about laying it down and am not in the mood to tear into it tonight. I thought maybe someone could add some insight into what I'm experiencing. I'm not sure if there are some knock sensors or something similar on the engine. The rattling sound however does concern me more than anything else.

If it makes any difference, when it fell over I was parallel to my garage door and the bike landed on the left side, with the slope of the driveway, it actually heeled over past the roll bars and landed on the mirror. I'm concerned that the impact may have done something to the engine although there are no leaks anywhere. I have floor boards which did fold up into the shifter but it shifted fine all during my 60 mile commute. Any thoughts or comments about the bike, not my stupidity, would be appreciated.

[Rambozo]

If it was a California model, you may have leaked some fuel into the carbon canister. It will run rich until that is cleared out of the system.

[fibersport]

It's a 48 state bike but good thought. Still wouldn't explain the rattling sound though.

[Erdeniz Umman]

It is not normal for the bike to be still running when fell over. Have you checked the bank angle sensor?

[fibersport]

That's what I thought and no, I have not looked at anything yet.

[DenverWinger]

With the engine running on its side - Wondering if maybe a stuck carburetor float....

Try this: Disconnect fuel pump power at the tank, disconnect and plug vacuum line at the petcock, start engine and run the carburetors out of gas.. Use the choke when engine starts to sputter to use the last of the fuel in the bottom of the carbs. After it dies, reconnect vacuum line and fuel pump.

This exercise "Should" drop the floats to bottom of travel and maybe restore normal operation if one was stuck.

[fibersport]

Now that's an interesting thought, will try that.

[fibersport]

Update:
I pulled the carbs off today and have not found any possible reason for the low idle. The rattling noise only happens around 500 rpm, at normal idle speed it's fine. The orange stripped hose that goes between the intakes under the carb is fine, as are the rest of the vacuum hoses at least as far as I can tell. To check the floats I blew into each fuel inlet and rotated the carb until the needle closed, they don't appear to be stuck. I have spark at all 6 plugs, however the left side plugs are a little black and sooty whereas the right side plugs are a more normal tan/whitish. I'm a little stumped, I have spark, I have fuel and I have compression - except it seems that something is not quite right. Any more thoughts while it's all apart?

Anyone know where the bank angle sensor is? Can't seem to find it in my manual.

[Erdeniz Umman]

It is under the trunk frame, on the right side.

[fibersport]

Thank you, will add to my list for tomorrow.

[fibersport]

Turns out it was fouled plugs. When I started thinking about it, the fact that my bike will sometimes put out a puff of smoke if left on the side stand for a few days got me thinking. When it fell over, it went past the roll bars and really laid down. That allowed oil to flow into the left valve cover, when I righted the bike and went to start it, some of that oil leaked past the valve guides an went into the left cylinders which then allowed the left plugs to get fouled with oil. New plugs and she's purring like a kitten.

Thanks to all who replied, having a bunch of ideas does help.

[BKL1664]

Check your air filter also, new plugs, new air filter means a lot, so often taken for granted.

[fibersport]

All good, thanks for the suggestion.