Just picked up a 95 1200 Sportster with around 4k miles which had been left for around 2 years. Cleaned the carb and replaced the slow / pilot jet, the bike will fire right up if gas is squirted into the carb but then dies. The bike will not start, replaced the plugs and the compression was 150 lb in both cylinders. It is a CV carb with Y72A stamped on it. The choke being in or out makes no difference. The airway from the pilot jet to the front of the carb is clear. Any help / suggestions welcome

 

Sounds like you're not getting any fuel to the carb. Check your fuel line and petcock to make sure they function. Then check your float and make sure that is adjusted right and filling.

 

We have fuel in the float bowl and can see gas squirting from the acceleration jet when the throttle is twisted. Will start and run for one or two seconds then die occasionaly.

 

My next guess would be to check all the jets and make sure they're clear. Since it will run when given fuel from the accelerator pump, but won't stay running, it appears that fuel is not getting into the cylinders consistently. There could be a vacuum leak or some sort of imperfection in the venturi that is messing up the carb pulling fuel from the jets.

 

Pull the carb apart and soak it in carb cleaner for an hour or so, wash it off with hot water then blow through all the passages with compressed air. There is a blockage somewhere in one of the ports, like the one at the bottom of the bowl. Then put it together with a new carb kit and follow the instructions to set it up correctly. I had about the same problem on my '86 but had to change out the carb to fix it.