infrequently won't start

Usually starts (always at the shop), but occasionally won't fire. Seems to not get gas. Other times, fires right off. Mech hesitant to start replacing parts without knowing what it is. Any ideas?

What year is it? Fuel Injected or carb?

It's an '89, carburated.

Also, when it finally does start, it sometimes backfires a little.

Seems dry when it's not starting when I pull the air filter. Certainly not smelly of gas or flooded.

That's hard, I wish I knew more about carburetor engines. Maybe someone with more knowledge will help you.

[sneak]

try the anti-afterburn valve should be located next to carb...plus the vaccum line rack on the fire wall. could have leaks ....will cause fuel diaphrams and dizzy diaphram not to work....or maybe the fuel nozzles in the float chamber in the carb are blocking up