Nope, throttle has absolutely no effect on the revs when it's stalling, which is why I'm lead to believe it's running gout of fuel, it behaves just like a car which has run out of fuel.

But I agree, no float window makes it hard. Apparently if there's not float window it means it's not something you adjust.

Tell me guys, I find two screws on either side of the carb, I'm guessing this is mixture adjustment for each barrel?