Originally Posted by yorkie_chris

Er taking the spacer off the needle drops it further into the needle jet, which leans the mixture. If you've taken the white plastic looking spacer out then it'll be getting no fuel low down at all hardly.

Put the needle to stock position with standard spacers and see what it runs like, then think about shimming it up or down.

Edit: whoever advised you to do that is a nugget. Running it lean risks melting pistons and exhaust valves and other expensive stuff.