Engine replacement help…

[Ogbign]

Ok so I had this boat 1978 IMP APACHE. With a 1990 4.3 v6 merc. Put a tone of money in it ran great the whole time I owned it, I sold it to a friend who says they only had it out twice within the last yr Something happened he took it to a mechanic an they said it has a bent crank. Well I bought it back havnt got it home yet to check anything, but the engine was in very good shape before. My questions are is a bent crank at all likely? I also know where a 5.0 v8 merc is cheap that’s turn key ready. The boat isn’t huge a didn’t come this big of an engine already, is there much if a difference in weight between the two engines ?

 

[Bondo]

Ok so I had this boat 1978 IMP APACHE. With a 1990 4.3 v6 merc. Put a tone of money in it ran great the whole time I owned it, I sold it to a friend who says they only had it out twice within the last yr Something happened he took it to a mechanic an they said it has a bent crank. Well I bought it back havnt got it home yet to check anything, but the engine was in very good shape before. My questions are is a bent crank at all likely? I also know where a 5.0 v8 merc is cheap that’s turn key ready. The boat isn’t huge a didn’t come this big of an engine already, is there much if a difference in weight between the two engines ?

Ayuh,..... Heard of a broken crank, but not a bent crank,.....

The 5.0 will be 'bout 4.5" longer, 'n 150 lbs heavier,....

 

[Lou C]

Sounds like it could have hydrolocked.

 

[Scott Danforth]

Most likely a bent con rod from hydro lock

 

[stresspoint]

bent crank LMFAO , ? is it twin turbo 1000 hp and had a miss fire , that might bend a crank on a 4.3 otherwise "not likely" might snap on if you took it to 7500 rpm.

 

[Ogbign]

Ya Iv never herd of bent crank either, but I got the boat home, before I left with it he said it would start but knocks badly, i checked the oil first and no oil on the dipstick, spun it by hand an checked it looks like some water in it. They obviously havnt checked it. So should I change the oil a see if I’m still getting water in it ? Or just yank it out ?

 

[stresspoint]

sounds like your " friend " broke it !

whenever i sell something to friends or family i make it a rule to give them a run down on house work> shyt that needs to be done after each use and preventive maintenance .shyt that needs to be done all the time.
also i add a you buy it you own it statement before any cash changes hand > tell them once you give me the cash its yours, if it breaks "" bad luck"".no agreeing to that they ain.t getting it ..as i don't want to be facing the BS you are ATM.

in your case , you have no idea what they did to make it run out of oil , no idea how it was ran , for all you know they could have blocked the intake with weeds or something and ran it flat out.

yea , sounds like its broken , pull the motor and get to fixing what they broke , not much else you can do at this point .

keep us posted with pics , i am sure some here will be able to diagnose what went wrong so you can throw it back in your " friends" face.

 

[Bondo]

Or just yank it out ?

Ayuh,... That's where I'd start,.... easier on a stand,....

 

[Lou C]

I'd be curious as to if the person who bought it would be offering any other information such as:
was it overheated?
did the oil filter spring a leak (unlikely)
did the owner back down too fast and cause it to hydrolock?
there are only a limited # of things that can cause that kind of engine failure, which as long as you have oil in it, it is running at normal temps, and you don't chop the throttle to cause a hydrolock, those kinds of failures are very rare.

 

[Ogbign]

oil was empty but had signs of water being in it, not milky either , not sure if I was drained an set over winter an got rained on, not sure. I pulled all the plugs out the block an risers water in them but didn’t look bad, I added 4 qts of oil all I had here. Still nothing on dipstick. No leaks anywhere. I spun it by hand with all plugs out, nothing abnormal. Also no noises. But where they heck my oil go ? Only holds 6qts I think right ?

 

[Ogbign]

oil was empty but had signs of water being in it, not milky either , not sure if I was drained an set over winter an got rained on, not sure. I pulled all the plugs out the block an risers water in them but didn’t look bad, I added 4 qts of oil all I had here. Still nothing on dipstick. No leaks anywhere. I spun it by hand with all plugs out, nothing abnormal. Also no noises. But where they heck my oil go ? Only holds 6qts I think right ?

They also sold the 5.0v8 I was loookin at.

 

[Lou C]

The 4.3 only holds approx 4.5 qts, less than the V8. Mine has never taken 5 qts for an oil & filter change.
If nothing read on the dipstick I wonder if the oil pan rotted through and the oil wound up in the bilge under the oil pan!

 

[Ogbign]

I can see under the oil pan if it went there itd be on my socks …

 

[Ogbign]

Inside the intake and risers are pretty dang rusty ….

 

[Ogbign]

It’s pretty dang clean for an 1990

 

[Lou C]

It is! No sign of water intrusion there

 

[Scott06]

Inside the intake and risers are pretty dang rusty ….

Would imply water down the intake And possible hydrolock. Does it still have compression. Still can’t explain where oil went… did they check the be fore use ? Guessing not ?

 

[Ogbign]

It is! No sign of water intrusion

Would imply water down the intake And possible hydrolock. Does it still have compression. Still can’t explain where oil went… did they check the be fore use ? Guessing not ?

It does seem to have compression, I havnt pulled compression check yet but spinning by hand I can tell it does.

 

[Ogbign]

I bought this boat a couple yrs ago, the starter had a bolt broke off in the block, the owner was using a board to jam the starter to make it work and using it like this until it got to where it wouldn’t hardly grab the flywheel, I pulled the engine extracted the bolt an replaced both with oem, old starter still wouldn’t grab so I bought a new Wilson, worked fine every since, after buying it back now. It was kinda stuck in gear took a bit to get it out but its in nuetral an will turn with key, but it sounds horrible trying to spin, sounds like an old starter that needs badly shimmed. I don’t hear any knocks or ticks turning over but flywheel sounds bad. Also doesn’t explain where my oil went …. I even pulled the plugs out the manifolds to see maybe. No fluids in any cylinders an plugs are used but nothing abnormal, I have found some small/tiny rocks/pebbles in the water side, I’m gonna pull the engine tomorrow an get pix if anyone cares to see ..

 

[stresspoint]

I bought this boat a couple yrs ago, the starter had a bolt broke off in the block, the owner was using a board to jam the starter to make it work and using it like this until it got to where it wouldn’t hardly grab the flywheel, I pulled the engine extracted the bolt an replaced both with oem, old starter still wouldn’t grab so I bought a new Wilson, worked fine every since, after buying it back now. It was kinda stuck in gear took a bit to get it out but its in nuetral an will turn with key, but it sounds horrible trying to spin, sounds like an old starter that needs badly shimmed. I don’t hear any knocks or ticks turning over but flywheel sounds bad. Also doesn’t explain where my oil went …. I even pulled the plugs out the manifolds to see maybe. No fluids in any cylinders an plugs are used but nothing abnormal, I have found some small/tiny rocks/pebbles in the water side, I’m gonna pull the engine tomorrow an get pix if anyone cares to see ..

most defiantly , i am also curios where the oil is going , ? does it have the correct dip stick .