1974 250 WR w/Bing dies

I have a new to me 1974 WR 250. She starts right up and runs fine for 10-20 minutes, and then she dies. She acts as if she's out of fuel. If you flood the Bing (pressing down on that thing on the left), she'll start up again. She's getting fuel from the tank to the carb, and I checked and she's getting a great spark.

So, I'm guessing I should take the Bing apart and clean it and see what's going on. The last time I took a Bing apart was in about 1975, so I kinda' forget except I seem to remember that they were simpler than a Mikuni.

Any ideas on what's wrong? What I should look for? Stuff I'll need to get?

check the tank breather is clear...when it stops, undo the tank cap and listen for inrushing air. ive seen this happen when wasps build a nest in the breather hose, vacuum builds in the tank and reduces fuel flow to a dribble...can be real hard to pick as you focus on the carb thingy for ages. Also well worth tearing down the bling and giving it a real good clean. note the jets in it for future reference. check the floats "float" and the needle and seat "seats". finally check the float level. plenty of info on Boing Cabs about to help you

Ditto on suprize's suggestions.

Does this pedcock have a screen above it in the tank. I seen stale gas dryup in the mesh of the screen.

I have three IH 154 estate tractors. My first was very cheap and I found out why. Inside the gas tank was a stone. It would move around till it plugged the hole above the pedcock. I'm in the middle of mowing when it would die. After a few minutes it would restart. Finally it stalled and didn't restart. I pulled the gas hose off the carb no gas. I opened the pedcock and blew into the hose as hard as I could. No problem then I flushed the tank. Food for future thought.

Thanks. The tank gas cap is a chrome thing with no breather hose (my old back in the day 1977 RM 250 had as I remember a hose coming out of the gas cap). Asking a stupid question, but how do I clean out the breather on this Husky cap?

it should have a small breather holes on the inner bit inside the rubber sealing ring that goes thru to the other side of the rubber ie just under the lip..i would soak it in petrol or kero or something then try to blow compressed air into the holes gently to see if they flow. these caps usually don't cause issues. the rubber hose vents are the most likely culprits. still check from the start to the finish. as Big bill says, check inside the petrol tap screen to make sure it flows enough fuel.

Thanks for the replies. I'll let you know how it turns out.