How to Install a Mercruiser Dry Joint Exhaust Manifold

[@ccccen]

I notice you had taken the hose at bottom , does this part of the ,can I remove at bottom to drain motor???????? I need to remove a manifold and need to drain it before replacing. where is that blue screw on plug goes to???? is that for draining engine too???.

[@d804s2]

i know the old wet joint style of manifolds and risers should be changed every 5 years... but how often should these dry joint manifolds and risers be changed out?

[@ON3L0VE]

What would happen if you had the restricted gasket on the bottom?

[@greatmusicgoodfeel826]

Thank You for information. Helps . Riser Bolts, No part numbers and 2x mercury dealers say they can not order them due to no part numbers in computer. Ya right, Any Ideas on where i can get 8x new 9 inch bolts . Thanks

[@watcherwatchmen7785]

I would just take off one of your bolts and measure the pitch with a set of thread gauges. You could also bring it to the hardware store and they have screw in style thread gauges you can use to figure it out. Buy a couple of the matching bolts but make sure they are longer than the old one, cut off the head with an abrasive disk or hacksaw, then cut a slot in the end so you can remove them with a flat head screwdriver.

[@jreuscher]

What are the bolt dimensions (2 guide pins) that you made in order to slide the manifold on? (i.e. length, size and pitch)? Thanks!!

[@leesire]

jreuscher I like how these folks answer your question.

[@danyel007]

I"m looking for the same answer

[@Vincegould]

They cut the old bolt off just under the head and slice a flat head style grove into the end for removal. At least that is what I gathered from this video. It’s brilliant.

[@satberhoxhaj3347]

if you can help out i looked a boat with a merc 5.0 temp was at 170-180, compression at 170-175, left riser luke warm right riser hot but you can keep your hand on it, engine vibrating very bad any thoughts??

[@Vincegould]

It’s clogged with rust.

[@silverstarflite135]

Do you sell manifolds/Dry Risers for the 7.4 454 block GM Engines?