Smoky bike, dies sometimes

[beef_brutality]

Hi everybody.
I've been working on a junkyard 1993 GS500 for a couple months.
Bike's been stolen, totaled, possibly in a flood, there were like 11 events on the VIN lookup before I bought it, but it was $300 so here I am.

Anyway, it took us forever to get the bike to start and idle and run, but we finally sorted it. Then we took FOREVER to get the idle set.
Then, it was running pretty good up until I noticed the clutch slipping.
When I replaced the clutch, I had a new problem- the bike would start smoking BAD and bogging down.
I weigh about 280 and i could only get it up to 30 MPH at WOT in second, smoking and backfiring the whole way.

I eventually came back to it, and we cleaned the carbs out, and it started running better, but it still smokes. With that, the right side plug is BLACK whenever it eventually dies on the side of the road, so it's either running rich or burning oil.
Now I have an issue where it seems to be running out of fuel way too fast. When it starts to bog down on me and eventually stalls at the side of the road, switiching the frame chicken to reserve seems to get me back up and running, (and with less smoke).
The weird thing is, when I get to a gas station, I'm only like 2 gallons or less away from empty.

I thought I had bad rings, and thought the smoke was burning oil, but I was on a ride with my friend last week and he told me the smoke looks more grey than blue. I've read here that the stock jetting is super lean, so I can't figure out why it (by all appearances) would be running super rich, and only super rich in the right cylinder.
The only thing I can thing of is that I maybe put the fuel petcock in backwards (the shutoff screw now faces the drain plug, not the side of the tank) or the fuel hose routing to the frame chicken is wrong.

I have the stock exhaust and a lunchbox filter, so I ordered new jets that match the matrix on this site (I can't remember what the sizes are off the top of my head). Other than that, can anyone imagine what the problem with this thing might be?

[J_Walker]

possibly burnt exhaust valve/improper exhaust valve seating, basically fuel is just blowing out the other end.

or the sparkplug is junked, and needs to be replaced.

or the sparkplug isn't firing at all.

sounds like your lack of power, seems like you're on one cylinder.

check the two easy ones first, the spark plugs.

Fuel
Air
Spark
Compression

[beef_brutality]

I replace the spark plugs, well the right one (left is fine) every 2 fill-ups.
I don't have one on hand to determine if it's black from soot or oil, at this time, though.

I will say, it does sound strong when it's running, definitely not one-lunging.
I'm going to try to buy or make a balancing tool to confirm it is running on both cylinders and how far off they are.
If one cylinder is running richer than the other, what could be causing that, other than different jets in each carb?

[mr72]

If one carb is running rich and they have the same jets then it could be a couple of things but I seriously doubt this is your issue.

Most likely one carb slide never comes up, or is stuck up, or the fast-warm-up jet ("choke") is stuck open on one carb. Maybe a float needle is stuck open or one side float height is really high.

But I think the black plugs is likely a red herring. If it's oil then that might be bad rings. When you say it smokes, what color smoke? Grey/blue/whitish smoke indicates burning oil, which probably means the rings are shot on one cylinder. That would also mean no compression on that cylinder. And that'd foul the plug (with oil) rapidly and also cause vacuum to be low on that side and the carbs/slide would not open.

Do a compression test before you spend any more money on this problem. IMHO.