Blown Motor
 

Last Week Took Boat Out For The First Time This Year. After A Hour Of Running Time. One Engine Made A Funny Rapping Noise Like A Machine Gun For About 3 Seconds And Locked Up. Found The Bidge Full Of Oil. Pulled Both Engines And Could Not Find Any Holes Or Leaks Any Where. Any Ideas What Happen? How Would All The Oil Come Out Without Any Holes In Engine Or No Signs Of Blown Gaskets

Re: Blown Motor
 

I had something similiar happen last year. One engine made clanging sounds so I shut it down, took it home, and the next day my bilge was full of oil. It ended up that I dropped a valve, cracked the cylinder wall, and water came in to the engine. Oil is lighter than water, so the oil came out of the dipstick tube.

Re: Blown Motor
 

Time to pull the plugs and see if it's still locked up. Then a compression and leak down test. Let us know how you make out--Lou

Re: Blown Motor
 

Same noise happend to my old motor, connecting rod snapped off and flipped over, the noise was the rod slamming into my oil pan. It didn't punch thru but it pounded on it enough to break the oil pan gasket seal. Check your oil level, if you are running what looks like a few quarts high you might have a bunch of broken parts down in your oil pan.

Re: Blown Motor
 

Engine Is Locked Up Solid Even With No Plugs In It
Oil Is All Gone, No Holes In Engine, No Signs Of Gaskets Blown
"strange"
Probally Never No What Happen
Well 2 New Crate Motors Going In Now, Just In Case The Other One Is Not To Far Behind. Season Is To Short In The North East To Take The Chance.

Re: Blown Motor
 

jhnrckr makes a point I forgot to include in my post and that is if you kick out a couple rods, the pan will be dimpled right below the side pan gasket. Usually with a hole(s) at the same point. When you get a chance, tear down the blown motor. Despite the mess you can usually get a pretty good idea as to what let go. First thing I'd do is look at ALL the rod bearings. A lot of guys think "a rod broke" yet the rod bearings look like potatoe chips which means you spun a bearing or lost oil pressure, the rod seized and then the rod broke. I could go on,but you get the picture. With the new engines, don't forget to break in the new cams. Easy way is to pull kill switch, crank on starter until you get oil pressure, light it up and run at 2000-2500 RPM for 20 minutes. Change oil/filter. More sophisticated ways but this usually does it. For what it worth. I'm sure you know all this and then some