I have an 84 brat with the stock carb that was starting good until the other day. Acts like no fuel when cranking but you spray some starting fluid it starts and runs prefect. when you shut it off it won't start back acts like it doesn't have fuel. Can't figure this one out any suggestions 

Fuel pump starting to fail would be my first guess. 

Replaced both fuel filters (front and rear)? 

Have a look through the sight glass to see if there’s any fuel in the bowl. It’s on the RHS of the carb. 

After it runs and you’ve shut it off and it doesn’t run anymore, will it start with some starter fluid? 

If not, does it need to cool off before it will start again (with or without starter fluid)? 

If your answer sequence is no and yes to the above questions, the ignition module in the dizzy could be on the way out. Replace this and your coil at the same time. If the coil dies it takes out the ignition module with it. Cheap insurance. Ask me how I know… 

Cheers 

Bennie

I believe the pump is weak did replace the filters about 200 miles ago. 

hadn't notice the sight glass but it is only getting about 1/2 on sight even when running.

will restart on gas pin ether but not on its own. cooling off doesn't help.

There’s a small dot on that glass site hole. It’s about half way up. 
 

Pump or float valve/needle. My opinion. 

The sight glass should only be at the halfway mark, generally at the marker dot as @moosens mentioned. 

Had a carb rebuild done? The accelerator pump might be on the way out. If it drives like a momentary flat spot when putting the foot in that points to the accelerator pump not putting a shot down the throat of the carby to get things moving. 

Also try pumping the throttle several (or more times) to get it started - that trick might help. 

Cheers 

Bennie