Yes, screw the nut on as far as you can get it. Then screw the muffler up against the nut lightly. Back the muffler up just enough to get the pressure nipple where you want it. Then tighten the nut against the muffler with a wrench.

Start the engine and run the engine at high speed for about one minute. Shut engine down and retighten the nut immediately while the assembly is real hot.

Enjoy,

Jim