Lower unit spraying water out of motor mount casing.

Hello,
First off I have the marina looking into this but wanted some education if possible.
My lower unit on an older 225 hp (1998) 3.0 L had trouble. So I bought a used lower unit with low end pickup. Same exact hieght as old unit. SO DEPTH OF MOTOR NOT ISSUE.
I had the marina install unit. I took it out today for test run. At low speed and in water the spray is not noticeable. BUT when I throttle up, water sprays from out of the midsection right at the motor mount covers located on bottom of midsection/just above lower unit. Towards transom.
The water is NOT coming out of joining area of the mid or lower. It comes out of the motor mount area.
The tell tale or pisser works fine. Just sprays water from the mounts on transom.
Now in the slip I lifted the trim and ran motor. Sure enough water was coming out of that section just not as strong. SO this is not a depth of motor issue.
The guy rebuilt the pump and moving it by hand was pretty snug.
Q: what could make water come out of there?
Q: could the seal of the pump be spraying inside midsection causing this?
Q; could the fitting attaching flow line be split? There is a LOT of pressure coming out under speed.

Again: The motor is exactly the same height and position on boat before changing unit and it did not have this issue.

Re: Lower unit spraying water out of motor mount casing.

So I bought a used lower unit with low end pickup.

Click to expand...

Is it the factory 2 or 4 hole pickup or a aftermarket with nose cone? If factory it sounds like the speedo pick up is not connected and spraying into midsection.

Re: Lower unit spraying water out of motor mount casing.

Hey FZ. Glad you picked up on this. So sir, if you don't mind I will elaborate some since you probably nailed the problem.

Mr. Dog. Look on the front of the lower unit, below the horizontal plate over the prop (anti vent plate) for a hole. It will be small, maybe .05" to .075". If that engine is like mine, that hole connects to a water duct inside the LU that allows ram water to go vertical to a tube, right there in the front of the LU and the tube winds up at your speedometer. When you changed LUs, if it has such, and you did not address it, Mr. Faztbullet nailed your problem. Put a hose on it.

Mark

Re: Lower unit spraying water out of motor mount casing.

Thanks for the direction to look into.
It has 4 holes I believe. Located on nose cone lower front. Not sure if factory or not. Has two high pressure hoses coming from nose area and into pump impeller. My boat has speedo on stern not motor. But that doesn't mean the lower unit knows that.
Only issue I have with your guys possible solution is. When in neutral and trim up enough to see motor mount covers water slowly comes out. I thought speedo was operated by movement forcing the water in and by pressure the gauge showef speed. When getting up to speed and at speed it is literally spraying hard enough to hit transomand rooster tail water up the back of the boat. Labor day wweekend and marina can't work on it till tues. So.....