on merc with gil gil/merc manifolds and stainless risers one of the tailpipes sounds louder and is much steamer that the other. Figured that it is not getting enough water. Checked it with temp gun but the manifold dosent seem hot. Also noticed that the engine has a slight milky oil? Is this sighs of a cracked manifold? The exhaust temp out of that pipe is magnitudes higher that the other.

thanks

thats what it sounds like to me. pressure test the manifolds. If you have milky oil you shouldn't run it very much without finding out why and fixing the problem.

Most likely a cracked manifold take the risers off and look at the dividers at the tops of the manifold. That is where they usually crack.
Get it taken care of. I had a little steam and ended up having some pitting on a couple exhaust valves due to the water dripping.

checked out boat tonight

1) running with all hoses attached pull the elbow and have water in manifold. Mostly rear cylinder

2) running with gil elbow water disconnected and no water

3) running with manifold disconected but water going throu the gil riser get water inside manifold

The heads are melin and have about 60hrs on them. Need to do a leakdown.

If the manifold was bad it would leak without the riser attached?

Reversion or the weld on the risor is suspect.

Be careful running the manifold with no water to cool it.

The Gil risers will generally outlast 2 sets of manifolds. If the riser is leaking internally, you should be able to where with it removed.

Was the boat sitting at the same angle as it does when in the water. If not, it could be reverting water simply because of the angle its sitting.

You need to pressure test the manifolds and risers either separately or together.

I've noticed one engine steams more than the other, not really excessive, but definately more. No milky oil. I have AquaPower manifolds now; If I go through the hassle to take them off I'll just plan to replace them.

What replacement manifolds are best?

replaced exhaust and all problems gone