How about this?? Turn the stock needle valve out about 5 turns from closed and then install a remote valve in the fuel line and use it to adjust the mixture. I've done this before on a cowled engine and it worked great! I did use some tubing on the stock needle to keep it from turning and I wanted to make sure that it was sealing and not sucking air. If you ever want to go back to stock, no problem. And no boggered up carb either. Try it, it really works!