91 psortster 1200 runs ruff and fuel spitting out of carb. Black exhaust smoke.

SOURCE: bike runs at Idle but dies when given gas

have you changed the fuel filter? you are not getting enough gas, are jets squeaky clean? there is a good fuel system cleaner in the USA called Berrymans B12. put some in the tank warm up bike then let it stand overnight and see what happens. if still no luck repeat process. if you still have same problem then get new fuel filter

good luck

SOURCE: starts ruff and smokes

check coolant temp sensor

SOURCE: 06 yamaha rhino 450. ran fine when parked 6 mos

foat problems buddy adjust float in the manual it is set to high so it is shutting fuel off take carb off take bowl off and adjust the metalk the little valve is hanging on

SOURCE: I have a 1998 Sportster 1200 custom that idles

I have the same bike, but never ran sea foam in it but ill tell ya when i put sea foam in my mustang it blew black smoke for a good while, but i thinks its normal for it to do that, i would run it for a while to get all that sea foam out of there, as far as the idle being rough what do you mean, cause mine idles funny too, but i was told its normal for it to be idleing like that. Man i hope i help you out some. You wouldnt know the size of the fuel line is would ya??

SOURCE: bmw E30, 316, 55 kw, 1987, M10 with carburater

Sounds like you're running rich.

First, change the air filter, and check that the air intake isn't blocked somewhere.

If that doesn't sort it out, it's the carb. They have an automatic choke (cold start), which could be sticking on and causing problems.

One thing it isn't is the timing belt (sorry Satanscash) as this engine doesn't have one... and even if it did, failure of the belt results in a very dead engine!