I was out testing my new motor today. This is only the second time out with the new power. I had been experiencing problems at idle, it was running rougher than it should have been. Docking was not an easy task. Anyway, after a full throttle run, I pulled all the plugs. I found some salt deposits on 2 plugs, #5 and #6. Upon closer inspection, I noticed salt water leaking from the manifold gaskets on both sides. This motor has closed cooling, so it could not be leaking from the engine. The salt deposits were easy to spot, there was no other conclusion than the manifolds were leaking. I had Gil WetOffshore manifolds and pipes. I was close by the marina, so I took it easy going back. I pulled both risers and found a good amount of water laying in the bottom of the manifolds. I pulled the manifolds, the cylinder head exhaust ports were clean, only had some soot in them. No water at all. The motor oil is clean, apparently, not enough got in to get past the rings.
The story ends with a phone call to Fred @ Trick Marine for a set of CMI's.

My question is, do you think that turning my engine into a water pump rather than an air pump would rob considerable power? Pushing water out the exhaust that close to the heads can't be good for horse power.

Vinny,
It's like p...ss in the wind.. Your right, dry it out as much as you can. Thats why you see big ugly mufflers hangin out the back of my boat. But no water till the end of the muffler. Good joice on the CMI's. Wouldnt have any other brand. You may have to look at jetting again when that thing really starts to breath..

Good luck with it..
Dick

Reversion? How big is your cam?

Not big enough. It is a 114 lobe seperation. 238* @ .050 intake 248* @ .050 exhuast. Question is , will this cost me power? I hope that after the CMI's are on, this motor comes to life a bit more.

Don't think it's costing power. Reversion is a low rpm thing. Sometimes raising your idle 1 or 2 hundred is enough to stop it.

I think you would lose a bunch of horsepower. I know I did when one of my motors Gil manifold sprung a leak. It first I thought it was a fouled plug and it ran OK at high RPM but the port motor was still twisting a little bit more. I Pulled the plug and water came out. Then the exhaust came out. Then the motor came out. and so on and so on.

PatriYacht,
I am not talking about a little reversion, I had a fairly good sized leak or crack in both manifolds. I am sure it was leaking through out the rpm range, not just at idle. That's why I am hoping it robbed some power.

Dangerous Dave,

I am hoping that you are right about losing power.

I had that happen on a 525SC It was discovered after a long run. We stopped for lunch and when I went to start up again the one engine wouldn't crank because water got into the cylinders. At first I thought it was the starter. Water doesn't compress to easy You will love headers because you can actually see the spark plugs

CoolTrips,
Did you notice that motor with the leak being down on power?

I didn't notice a power loss but then again we were just cruising around 3500 RPM most of the time. Once I got the engine started I pulled off the hoses on the manifolds and let them run dry for a minute to clear the water. That engine seems fine now. I went with Hardin Marine lowers as they fit the risers. (didn't want to spring for new risers, silent choice etc.)

Mike