djm

I need to tighten my exhaust manifolds but don't have the Merc manual. Does anyone know the correct torque figure for the manifold bolts and the bolt size? Is there a specific sequence? I figured I'd start at the middle and work my way out. Thanks

Pwrbt33

DJM, you are on the right path by starting in the center and working out. Your exhaust bolts should be 3/8 diameter and they should be torqued to atleast 30 ft pounds. Once you torque one side go to the other and then go back to the first side and do them again. The bolts will actually stretch, thats how a bolt stays tight. Start in the middle and go back and forth till you get to the outside bolts and then you should be ready to go.

Pwrbt33
Offshore Performance

djm

thanks for the reply, do you know what size the head of the bolt is? Looks to be around 12mm if it's even metric. I don't feel like lugging every socket & wrench in the garage over the boat slip.

Pwrbt33

DJM,
The head size should take a 9/16 socket. If you are using allen head bolts it should be 5/16, if you are using 6 point header bolts it should be 7/16 and last but not least if you are using a 12 point head bolt it should be 3/8. If not any of the above just use lots of super glue and hope for the best !!LOL !!

Pwrbt33

RickR

It's a good idea to retprque after a couple of heat cycles. I am always amazed hope much the bolts loosen up (gasket compresses)

djm

Thanks for the help!!