I know that I have seen posts like this but not sure if I have diagnosed correctly. Just bought a bike and familiar with older cars but bikes are newer to me. 1987 savage (of course). Has emission control. Severe gas leak may be from a number of sources as it is a "mechanics special." Ran fine for a while mostly was starting 2 times a week til I could fund its registration. Now after a 15 mile ride was coughing sputtering and leaking gas. Looked like it was coming out of the bowl vent of the carb above the hose that leads to the emission control. Also leaking oily/gassy drips from air box drains. Read about petcock mod. not sure if that would fix but the air filter was extremely dirty. got a new one when I saw it. CAn a really dirty air filter act like a choke and flood the carb uncontrolably which might flood the crankcase? Does the new metal cone air filters work better, and is the breather hose affected at all from this change in design? I cleaned the carb when I bought it, but might the float be sticky Seemed pretty loose when I cleaned it. Any takers?

Could be one of  two things.  

1) float problem of either float hanging up on something or dirt may have gotten into the valve seat.  Requires dropping the fuel bowel and checking.

2) Diaphragm in the petcock may be leaking.  To check this, pull the hose that runs from the back of the petcock to the right front side of the carb.   It shouldn't have gas in the line.

anybody else? I put in a new foam filter and looks to be running OK, we shall see.