Got an 84 2WD carb'ed truck that I have rebuild the carb in. Been running fine until two days ago when I noticed starting to stumble and idle rough. Gotten bad enough now that it won't idle but will roll down the road 55 MPH. I can smell the unburned fuel. Question is...what would cause the carb to overload? Float sticking is the only thing I can think of. Any way to tell without yanking the carb down?

 

I'm guessing this is a stock carb. there's two soleniods on your carb. one's a fuel cut-off & the other an idle circuit.
check for connections.
I'd also recheck the fuel float operation too.
the float which controls the fuel needle valve & seat (if not adjusted properly) will allow too much fuel to enter the fuel bowl causing flooding, loading up or no idle.

Hope this helps.

Mike

 

It is a stock carb. Thanks for the suggestions. FSM shows the fuel line being mid-level in fuel window. Assuming the truck is on level ground, should this always be the case? I peeked at the window last night and saw no line which first made me think the bowl was empty. Given that it runs, it must be that the fuel bowl is filled to the brim...owing to the float not working correctly?