Fuel lines

Thanks for that...it makes perfect sense to me. What doesn't make sense is why there are fuel lines so low to the ground and so far toward the rear of the bike. The snap/cut appears to have happened on lines way past the carburettor. I'm re-checking Haynes pg 71 fig 2.3 (carb assembly) and notice 'vent pipe' and 'overflow pipe'. Is the overflow pipe leading anywhere or just open?? Possible that the carb is damaged and squirting fuel out the overflow pipe for some mysterious reason?? I admit there may be some anomalies in my reporting....will get a fresh look in daylight tomorrow (minus rain).

I agree with Gary, Your second post sheds a bit more light on what you are experiencing. Also, both of the tubes that you are describing need to be open on the end. The vent to allow fuel into the float bowl and the overflow to keep the engine from getting filled instead.

More updates.....no Gman, the bike has been a daily driver, not sitting in storage. Im very certain there was no fuel pissing out when I inspected prior to purchase, so I can only conclude the fall I took somehow disrupted the carb unit.
Today I had a good long look at it, and yes, fuel running out of overflow line when engine is running. Surprisingly, I got her started quite fast today(3d or 4th kick). I went for a long ride to the top of a hil and inspected her in the sun. HOWEVER, the nightmare began when I tried to start her again. 30 minutes of kicking later (thinking I had the knack) I gave up and decided to jump-start downhill. No go...I used a lot of permutations (1st, 2nd with decrompesser lever in, letting go of the decompresser AFTER dropping the clutch)...she would splutter a bit, fire very hesistantly until the back wheel locked. I had 5 km of 50 degree downhill to try this...I had AMPLE time to play with the kill switch (in case of dirt etc), the ignition barrel/key, choke settings etc, all while free-wheeling downhill.
So, is this connected?? Has to be a 'maybe'. What are the chances that the inlet needle valve is stuck (BTW, what number is that on the Fig.2.3 Haynes carby diagram? 6?) AND something else is wrong (like the CDI unit or something else???). I know I need to be methodical and work with the process of elimination, but the bike is so d**n new to me!! The previous owner seemed very honest and trustworthy (I used to be a cab driver and can gauge people pretty fast), so I don't suspect he had a bag full of 'unwanted surprises' thrown in with this deal. Any ideas where to begin - short of what Im already doing, which is looking for a Yam mechanic!

Dood,
Welcome to the forum. First off, don't do anything drastic like change the stator.
Lets just relax for a moment and think about this.
Bike running good, you fell off, now bike running bad with black smoke and fuel running out of the overflows. Must be flooding the carb. Most likely cause, stuck needle or somehow the floats got stuck or bent when you fell off.
Very unlikely anything else wrong. All the symptoms you descibe - difficult to start, fuel running out the overflow and black smoke point to this - an overly rich condition because the needle valve is not seating and shutting off the flow of fuel into the carb.
Turn the fuel tap to prime. When fuel starts to run out of the overflow, give the float bowl a couple of sharp raps with the plastic handle of a decent size screwdriver.
Very occaissionally, this will dislodge a stuck float. If the fuel running out of the overflow stops, you have success.
If not, take the float bowl off. This can be achieved with a short screwdriver without removing the carb. Check the float is properly placed, in particular the pin it pivots on, and check the float valve/needle is actually in place. Maybe you came down hard enough to bounce everything around and actually dislodge it.
Always do the simple stuff first.
Mick

Diverted from fuel lines to carb issues? It is a carb issue.

There is only one fuel line on your bike. It goes from the fuel petcock to the carb. That's it. You can imagine that on a gravity fed fuel delivery system that the engineers would not really divert fuel from the fuel system above and run it under the bikes engine and frame. You are simply looking at pieces of line that allow any lost fuel from the carb vent and or the float bowl drain to be safely expelled to the ground below and not on the hot engine or anywhere else important.

Now re-read Micks post and do what he says...

Hmm. Managed to sort most of the problem by jiggling the float, etc.
If its still blowing black smoke, although now running reasonably well and not leaking fuel out of the overflow pipes, one wonders whether the float is set too high. Quite conceivable, since it appears your carb has been upset by your unscheduled dismount.
If you read your manual, you will see that there is quite a range of measurements that are acceptable for float height. Try setting the float a couple of millimetres lower. (This is a larger measurement, since you measure back to the carb body.) This may affect mixture enough to do the deal.
BTW, in this instance, when we say needle, we mean the little needle and seat type valve arrangement that is closed off to stop fuel flow when the floats are high because the float bowl is full of fuel. The closer your float is set to the carb body, the "higher" it will be, and the higher will be the fuel level will be in the flaot bowl. This can enrichen the mixture.
This is a little fiddly to get right, since there is a little spring loaded pin in the needle in my carb, so you have to judge carefully when you actually have the needle seated, but if I remember correctly the haynes manual is pretty clear on the how to.
Anyway, it might not be the problem, but its realtively simple, and free if you do it yourself, so its worth the try.
Mick