That would do it...

Also dialing the regulator screw in is leaning then engine out.

If it surging its already lean.

Always on YS engines surging is lean.

special Note...

The throttle barrel seal has a flange on it. This flange goes toward the engine when on the barrel. You can't install the barrel from the needle valve side, as the flange will be damaged. You have to insert the barrel from the exhaust side and push it all the way through...This will keep from damaging the new seal.

Troy Newman
Team YS