I just finished rebuilding my 350 merc new cam manafold and carb. when breaking in the cam i noticed the right exhaust riser and elbow were almost too hot to touch and the left side i could lay my hand on. during tear down i had both exhaust manafolds boild out and re powder coated so there is no rust inside and water flow to each side seams about the same. I am afraid to run the boat in ths condition with the engine cover in place and don't want to burn up a new motor. This one has me stumped any help would be great thanks.