Jetting for a single carb conversion

[vtdrifter]

I have a 78 xs400e that I just converted to a single carb manifold. Full disclosure: the engine was racing at idle with my factory setup so I pulled the carbs off to clean them. I broke the tip of the pilot screw off in one, couldn't get the tip out and decided the conversion might be cheaper and more fun.

My bike starts and runs pretty evenly with the choke pulled halfway out. Putting the choke in more kills the bike even after 10 minutes of idling. I'm currently running 142.5 main jet with stock everything else as far as I can tell. My pilot screw is set 3 turns out. Reading online suggests I need to go up a size or two in the pilot circuit. Is that correct? Do I just need a larger pilot screw, or also a larger pilot jet?

Is there anyone who is running a 2 to 1 conversion with a bs34 carb? I'd love to have a starting point for all of my jets.

 

[Maxim-umm]

Well, what you have is your starting point. Your "choke" is an enricher. So when you pull it out you're adding fuel. So if it only idles with choke 1/2 out, then dies when choke is off, I would speculate not enough fuel. From that point start jetting accordingly. Larger mains, pilots, moving your needle, adjust idle, sync. It's a trial and error type science, adjusting one thing at a time then testing. Adjust, test.