exhaust manafold for 7.4

[jaxnjil]

exhaust manafold on starboard motor, starboard side, is leaking around at point where it bolts on head.

hope its a gasket, but suspect bottom could be rusted out of manifold.

long time since post.

looking for comments on which manifolds to buy. if this one is rusted out then will likely have to change all 4.

getting ready to remove riser and manifold now. will know in a couple of hours where leak is


any and all advice and comments welcome.

 

[jaxnjil]

ALREADY MESSED UP

mod please move to mercruiser i/o section

 

[Fun Times]

ALREADY MESSED UP

mod please move to mercruiser i/o section

Welcome back jaxnjil, I found your topic over in the Merc O/B sub-forum so I went ahead and moved you on over to the I/O forum.

Hope your issue isn't to severe, let us know what you've found thus far. Good luck.

 

[Bt Doctur]

there is no water connection where it bolts to the head, so if you have a leak there, their already shot .

 

[jaxnjil]

found that out bt doctur; also a leak at the manifold-head would result in a exhaust leak in the engine compartment.

what i did find to day after i got a manifold off; there are 2 threaded plastic plugs in the manifold facing in-to the head. casting plugs??/? they take a large tork scocket to r&r.

any way these are dripping and there is a drain+circulation hose fitting on the bottom of the manifold. it appears to be made form the same material.

these are 2000 M I P 7.4 B III's.

have had the boat layed up for 3 years and not sure if this played a part in the leaks. 3 of the 4 drain fittings are leaking at the threads and all 4 exhaust manifolds have one or both the casting plugs leaking.

my first thought before seeing how they are made was, leaking into the exhaust port and head. the one i have off seems sound as well as the riser and riser spacer.

other than the weight of the manifold and riser, will not be to bad to work on in the boat. port side of port motor a little tight but can remove a floor cover and get to it.

thanks much for answers.