exhaust manifold

[boatguy19]

hi all, i have a 82 searay with a merc 2.5 120 horse engine. im having a problem with the exhaust manifold, the last bolt that holds the manifold on keeps snapping off its good for the whole summer and then it snaps. this is the second year in a row that this has happened, the last time i had it off i put a straight edge on it and its good. need some thoughts on what the problem could be, other than that the boat runs really good with no problems, thanks in advance for any help

 

[choochooharley]

Re: exhaust manifold

Are you replaceing the bolts with the same hardend bolt or just one with same threads and length

 

[Brentathon]

Re: exhaust manifold

Was it torqued properly?

 

[boatguy19]

Re: exhaust manifold

i am using the bolts from mercuiser, and as far as i know you cant torque them . you can barley get a wrench in there, its just that one stud im having problems with.