232 exhaust manifold questions

Lklemm1

My 232 manifold seems very hot. Is there a way to check if the heat riser is opening? Any one know how hot the manifold temp should be if checked by a inferred gun? Any other reason the manifold could be getting very hot?

Geoff

Too lean a mixture can cause the exhaust temperature to rise, as well as retarded ignition timing, and valve timing out.