Sam , go have a look at the same website I mentioned re the muffler.

There are linkson the site that will take you to the section covering the Fox .46.

The guys who post that website seem to have all the answers on the idiosyncrosies of Fox engines and if you get stuck, just drop them an e-mail.

They helped me out with my .74R and also my .40 ABC, which now really perform after incorportating the changes they recommended.

In fact the Fox .74R now outperforms my Super Tigre .75R and the Fox .40 ABC is the best .40 sized engine I have in my "hangar"