My manual states (for gasoline engines):I'll see what I can find for the manifold for you, too...
Be sure all the old gasket material is cleaned off the
mounting surfaces on the manifold and cylinder head.
Always use new manifold gaskets whenever the mani-
fold is removed.
1. Position the manifold gasket, and the manifold,
over the mounting studs.
2. Install the six nuts and lock washers and tighten
the center nuts first. Then alternately tighten the
remaining nuts toward each end to 40-50 ft. lbs.
3. Place a new gasket between the manifold and
the muffler inlet elbow and install the two bolts.
Tighten the bolts to 40-50 ft. lbs. torque.
4. Connect the fuel line at the carburetor sediment
bowl and the air intake tube at the carburetor.
Open the fuel tank shut-off valve and check for
leaks at the carburetor.