Sizzling from my Valve Cover/Case...

Hey everyone!

Bought my 83 XJ750 Maxim a couple years ago for a steal, and ran well enough till it didn't. The seller used gasket spray instead of replacing donuts so I had some consistent leakage. Couple things came to light as I investigated:

• Seller just sprayed gasket sealer around everything.
• It's possible two of my outer gasket bolts got overtorqued by the seller.

I spent back and forth time with Len (f***ING LIFE SAVER!) and got a new cover gasket and all the appropriate donuts (with application tool). Put everything back together. I avoided using a torque wrench based on comments in various threads (but went a bit past hand tightening). Here's where I'm at after first ride since maintenance:

• No more leak at original leak point (left side front corner outer bolt)
• After riding appears to be some leakage further down the valve case, along the long fin near the opening for water flow.
• A sizzling sound coming from somewhere near the valve case - sounds inside BUT I couldn't see any bubbles, oil, etc.

Here's my questions:

1. What happens if I have the over torque issues? is there an easy replacement or is the valve case what got damaged?
   
   
2. It is INSANELY hot in NOLA today (100 degrees at 9am): is the sizzling because of overheating?
   
   
3. Do I need to consider tightening the gasket bolts further (I checked the gasket lining and it's lined up with no gaps - though it's not a perfect fit, being after market and all).
   
   
4. The old gasket was more or less bonded to the valve cover/case. I had to carefully chip it away from the metal. Could the sizzling be the rubber getting up to the temp and bonding?