Knocked my bike over, why's it running poorly?

[akpasta]

Yesterday my girlfriend was sitting on my 64' Superhawk and she fell over. Haha. The bike seemed fine. No cosmetic damage, it didn't hit hard, and fired right up and took me home fine and to work this morning fine. Ran great. But today at lunch it suddenly started running like crap. Seemed to come out of nowhere. It will idle and rev up okay on the stand (some bogs), but under load it just gasps and has no power at all. Both cylinders seem to be running and the points seem to be opening and closing and timing doesn't seem to have slipped. All I have at work is a screwdriver, so I couldn't check the timing, just pull the points and stator cover and observe.

Obviously I'm going to have a closer look when I get home. But I'm wondering, what can go wrong when you tip a superhawk over on its side for a second? It was down on the right side, if that makes a difference.

Gonna try pulling the float bowls off and observe. Also gonna check if gas got into the crank case, per Davo's recommendation. Any others?

Oh and by the way, I made sure to ask HER if she was okay before freaking out about the bike :) gotta keep up appearances.

Thanks.

[Tinman]

My guess would be the float bowl is stuck as that would be the only thing that isn't fastened down by a screw or nut, unless something wasn't tightened. Pretty easy to check and fix.

[akpasta]

I pulled the float bowls off and checked the floats, they both seem to function normally. I pushed them up, and let them go down to make sure gas was coming through. They're not overflowing either, as I imagine I would begin leaking gas out the drain hole in the float bowl if the carb were flooding due to a float problem.

Also my oil doesn't appear to be contaminated with gas as Davo suggested. It's basically at the same level it was before and it doesn't smell like gas at all. It's too dark outside to change it now, but I guess I'll try that tomorrow just to experiment.

I checked my timing with a strobe and it's exactly at the same spot. It doesn't appear to be electrical. I removed the tank and seat and couldn't find any broken wires or loose connections and both sides get spark and the electric start still works (strong charge). Both sides have compression too.

I feel like this has got to be a carb/gas problem. It just gasps and bogs when you try and accelerate from a stop and then runs like crap, bogging like hell. Putting the choke on makes it worse, so I imagine I'm not running lean. Also my plugs look normal, same as all the other times I've checked em.

Stumped.

Anyone else have any ideas?

[akpasta]

I believe I've narrowed the problem down to the left side. That side has always run richer than the other side, but I've put thousands of miles on it that way and it's never been a problem or affected how the bike runs. It hasn't even fouled a plug ever (made it stop producing spark), although plugs are pretty dark.

When you try running one cylinder at a time on the stand, the right side idles fine and revs up just fine. The left side idles a little lower and bogs and doesn't have consistent rpms when you rev it by itself.

So what now?

[Jlovvorn]

Left plug cable partially broken or detached from cap or pulled from coil socket, left carb bent and not tight to intake, choke system bent or broken and not lifting both sides at same time, plug cracked or broken from impact?

[akpasta]

I'll try the plug lead tomorrow, but the fall really wasn't that bad. It was seriously such a minor fall. Came down on right-side passenger peg and throttle grip, and also on my girlfriend, she was sitting on it when she toppled over so she slowed it down and broke the fall. Effects weren't immediate, appeared about 5 miles of riding later.

Couldn't be bent carb or choke, weren't really involved in the fall, could be plug wire I suppose. But wouldn't the spark be shitty if the wire got yanked?

My friend suggested gunk or rust shaking loose in the tank and coming down into the carb and clogging it, but then I'd figure I'd be lean, not rich. And gas is coming into the carb and getting into the engine, I've observed that just fine.

[kfsrq]

How about airflow? If your left air cleaner has started to fail, and filter material is clogging the way instead of just blocking grit, there might not be enough air for the left cylinder to run fast.

I know this is far fetched, but some air cleaners are over 40 years old and any imaginable sort of decay is a possibility to consider. It is conceivable that the fall caused some sort of disintegration in an air cleaner.

How about checking connections in the vicinity of the coils. I have taught my wife that many failures are caused by a loose connection, and many more are caused by an overlooked loose connection. And she has reminded me often enough that I am glad I told her that.

Here's a third (feeble) straw to grasp at. Check the screen in the fuel tap. If crud is partially blocking flow to the left carb, it may be getting enough gas to run, but not fast. I think this straw is particularly weak, but I cannot utterly dismiss it. (edit -- oh, I see you checked this)

Best of luck.
Keith