Water in the oil?

[81 Checkmate]

Been a number of years since I have been on the site. So hi!
1986 5.7 mercrusier
My son bought my old boat I sold 5 yrs ago. We put a new fresh rebuilt 350 in it this spring. Used the old exhaust manifolds and risers. Long story short - we had to replace the manifolds because of internal cracks. Changed oil several times. took to the lake and it ran it a few good runs - about an hour of run time between stops. Pulled the boat drained the oil and all honey brown.
Brought the boat home and over the weekend we did some carb adjustments and tuning . Checked the oil and it is getting water in it again. WTH
The boat is sitting in the driveway with the trailer Tung high so water would drain from the bilge area
.
Question - Has anyone ever experienced getting water in the oil from using muffs on a hose with the boat tilted back to far?
I'm thinking maybe that when we turn the motor off with the hose still running the water is draining back into the cylinders from the extreme angle on the motor. Dip stick level is not rising.

Your thoughts?

Thanks,
Mike

 

[Bt Doctur]

what about the elbows?

 

[Rick Stephens]

I would not be satisfied until I pressure tested the block. Block off the hoses going to the manifolds, pull the line coming from the transom and make up a fitting there to put in 15 PSI. See if the water jacket holds pressure.

 

[81 Checkmate]

I pressure tested the block with the old manifolds off - worm clamped 4 beer bottles on the manifold hoses and pressured up the intake hose from the drive @ 20 psi and it held there for over an hour. That's when I pressure tested the old manifolds and was getting air bubbles in the exhaust passage - No 7 on the pass side and no 2 on the drivers side. No elbows - Thru hull exhaust from the rubber boot coming from the risers. Been doing this a long time and its kicking my a""""

When I was checking the risers I noticed the slots in the round exit part that water goes into the exhaust. My thinking was with the boat tilted so far to the rear that when I shut the motor down it is dribbling water in those slots and back into the cylinders.

 

[81 Checkmate]

On another question. I was looking at new risers today. Noticed a part number difference and wanted to now if any knows what the difference is between the -1 and -2

Sierra brand - 18-1970-1 Riser Elbow - 15 Deg
Sierra brand - 18-1970-2 Riser Elbow - 15 Deg

Thanks,
Mike

 

[Bondo]

Dip stick level is not rising.

Ayuh,....... I'm gonna guess yer seein' condensation in yer oil,......

If the oil Level ain't risin', it ain't taken in water,......

'n, No,.... runnin' it on the wagon ain't a problem,.........
I've left the hose runnin', on a not runnin' motor, Many times,.....

 

[81 Checkmate]

Thanks Bondo for the reply - Glad to see you are still kicken it! We are just going to take it this Sunday to the lake and see what happens.