Bike dies without the choke??

[PRoberts317]

1983 XS650 Heritage Special: stock everything except K&N pod filters replacing the air box... pretty standard.

Bike was starting to "miss" or feel like it had a rev-limiter at about 3500-4000rmp, especially in 1st and 2nd gear... rode OK (better anyway) at night, but started missing a little worse during the day. I'm thinking it has to do with air temp. and maybe I need to adjust my mixture screws.

I screw em in, screw em out... no change... screw em in so far that i foul my plugs with too much gas (I think). So I change the plugs.

I pull the carbs; float bowls are looking clean. I pull the mixture screws and clean the passage they rest in; clean. Screw them in, then pull them out 3 turns. Fires right up (with the choke on) dies when I pull the throttle. Fire it up again, let it run for a while (choke on) dies when I release choke or pull the gas.

Same situation at 2.5 turns out and 2 turns out.

This has to be something obvious, guesses gentlemen and ladies???

 

[Ghetto]

Do you have new o rings where the mixture screws go?

 

[5twins]

My guess would be plugged pilot jets or circuit. When you pulled the mix screws and cleaned the hole, maybe you forced gunk back into the pilot circuit.