Problem with new motor

robbyr1

Petty Officer 3rd Class
Joined
Oct 23, 2009
Messages
99
~~I need help working on my boat. I have a 2001 Glastron SX175 with a brand new Volvo 3.0L 4 cylinder, 140HP inboard/outboard. I replaced the motor last year and it broke-in fine. After I changed the oil after the 20 hour break-in I started to notice some problems. It had a hard time starting (horrible, screeching sound, hydro-lock?), and had milky oil. I changed the oil and ran it, milky oil again. I did a compression test: 1,2 & 3 cylinders were fine, water shooting out of the #4 back cylinder. I drained the oil, took out the spark plugs and squirted some oil into the cylinders (hopefully preventing any rust) and shut it down for winter. Now I want to figure out what's wrong.
A couple clues: 1. My brother and I put the motor in. He is a car mechanic and helped me with most of it. I don't know much about motors, just enough to make me dangerous but I'm handy. I bought the motor and manifold new from Michigan Motorz and had to switch the riser, water pump, alternator, carb & electrical from the old motor.
2. When I installed the restrictor plate for the riser, I installed it "this side up" as it is stamped on the plate. After doing research I found that Volvo actually had it wrong and "this side up" was supposed to be down.
3. One time when I was out on Lake Michigan I let a friend drive and he "punched it" accelerating way to fast for all of the weight that was in the back. The bow of the boat came way up before I told him to throttle down. I believe that the potential was there for water to come back up through the riser (and into #4 cylinder).
4. I don't think it's cracked block. I replaced the motor because the previous one had a crack in the block between the #2 & 3 cylinders. This made me keep my eyes glued to the temp sensor on the new motor and I never saw it even get a little bit over normal temp.
5. Something else?
What do you think? Thanks for reading, have a great day! Rob
 

aerobat

Master Chief Petty Officer
Joined
Jun 1, 2011
Messages
842
~~remove your riser and look if you find evidence of water ( rust particles ) in the exhaust passage. water intrusion from gunning the engine is not likely because the exhaust gases prevent water to climb up in this moment. when all the odds are against you water can enter the engine when you cut the throttle immediately being on plane and having much weight in the back. but when you changed the oil and it runs milky again and again this will not be the answer.
i guess you will find much rust in the riser exhaust passage and have a cracked riser or a improper installed riser gasket. oher possiiliwould be the headgasket.

in any case you have to sort it out quickly or you will ruin your new engine.
 
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