Muffler mount leak

[cub2000]

I've just bought a Jetpro v2 muffler to mount it on my new 290 BB head engine. Even I'm just running easy idle to break in the engine, there is fuel/oil on the gas tank from the muffler mount to the engine. I even bought a copper gasket to put it in between and it seemed to help with the majority of the leakage, but there is still some fuel/oil on the gas tank. My friend tells me to go sand the muffler mount, but it seems flat to me.

Anybody experienced the samething and what did you do to stop it?

Any advise is appreciated.

 

[Clubin]

The copper gaskets aren't great for sealing surfaces that may be a little warped. Take the pipe off and very carefully file the surface of the flange that mounts to the cylinder. Use a standard gasket. Warm it up and tighten the bolts again, then put a dab of silicone on the bolt head to keep it from ever coming loose till you waht to take it off.

I also use just a very small ammount of silicone on both sides of the gasket.
Has to be high temp engine assembly sealant.

 

[Bigger the Better]

Make sure you are torquing the bolts down with a torque wrench. It is very important to tighten it to the spec. You will think "Holly &^%$" when you torque it. I also use ZAPII on the bolts to make double sure they don't vibrate loose.