2001 mercury 150 EFI will not turn a full revolution

[coreymon]

ok i am working on a 2001 mercury 150 EFI. lower unit is removed plugs removed. here is the problem: i can not spin the crank one full revolution. it goes around fine 90% of the way but it gets to a particular point and stops. fresh water only, new lower unity right before it stopped. i have pics and a vid if needed...

thanks

 

[Maxz695]

Re: 2001 mercury 150 EFI will not turn a full revolution

sounds like a broken connecting rod stopping the crank from rotating fully around to me. take out the plugs and use a flashlight to see if both pistons are moving or do a compression check if not tear the engine apart to check the damage

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

all of the pistons are moving. i am going to remove the cylinder covers. first time getting this involved on an outboard. any advise is truly apretiated and welcome...

 

[Maxz695]

Re: 2001 mercury 150 EFI will not turn a full revolution

before you dismantle anything it might be wiser to remove the Lower Unit and see if the problem is still there. if the engine turns freely at that point it,s in the Lower unit not the engine powerhead

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

here is a vid of what i can see now the lower unit is removed

 

[Big flop]

Re: 2001 mercury 150 EFI will not turn a full revolution

Good job with vid.
I would turn it clockwise till it stops.
Stick something in each spark plug hole & find
the piston closes to the top (TDC) &
Remove that cylinder head.
likely something on top of piston
or like max thought bad rod?

 

[Faztbullet]

Re: 2001 mercury 150 EFI will not turn a full revolution

Pull the heads and inspect ......

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

thanks for the input. i am going to pull the powerhead off next weekend. i have done this before on a 75 merc to change a gasket, but that is as far as i have gone with ob's. i have a full shop manual. after the powerhead is removed i will take off the head covers. if anyone has any sugestion about doing a tear down like this i am all ears. i uderstand that that this will be expensive and time consuming. i will provide vids along the way...

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

i will be taking head covers off tonight. any advise on removing all of the painted over bolts? do i need to knock the paint off before i put the socket on so it does not slip and round off the bolt head?

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

i got the port head cover off before the rain started. middle piston is shot. top of piston is crumbling/ there is a crack in the piston. any idea what causes this?

 

[Maxz695]

Re: 2001 mercury 150 EFI will not turn a full revolution

water and overheating. Lack of flushing the engine

 

[joezek]

Re: 2001 mercury 150 EFI will not turn a full revolution

Nice picture. Looks like water got into the cylinder. Notice how that cylinder is missing a ton of carbon? Water turns to steam and blows off the carbon leaving clean spots. My guess would be that the gasket was leaking a little bit, possibly it overheated and warped the cylinder head causing water to get into the middle cylinder.

Long time ago we got a steal of a deal on a boat with a "seized" 115 Evinrude. After a few hours of spraying WD 40 in the spark plug holes and slowly working the flywheel with a pry bar, we got it to spin over. After that it started and ran perfectly for the next 5 years. The previous owner had said that the engine slightly went below water at the boat ramp, sounded like BS to us. Anyways just wondering if we actually had a cracked piston that somehow survived after unsiezing it.

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

starboard side is off and that side looks fine. i can spin the crank freely now. my guess is the chunks of piston from the port middle were hitting the head cover causing it not to make a full rotation. the port middle cylinder is very rough. next step will be to pull the powerhead.

1st big question:
what do i do about the trashed cylinder? (i will have pics of the cylinder in the morning if needed)

huge thanks for the input...

 

[Faztbullet]

Re: 2001 mercury 150 EFI will not turn a full revolution

It maybe water related as it is clean and eroded on exhaust side of piston but most damage is on the intake side (picture is rotated)and head is still full of carbon. I would send that injector and ECU off and have tested before I ran it after it was repaired. Its a EFI so .020 is max you can bore it on a stock ECU(cant richen cylinder up)

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

is there a sleeve that i could replace on the efi cylinder? if so, is this a better option than boring it out?

 

[Faztbullet]

Re: 2001 mercury 150 EFI will not turn a full revolution

It will be cheaper and just as reliable if that cylinder can be bored. On a 2.5 block the sleeve goes to the bottom of the bore, so it a little more time consuming in removing, replacing and port matching thus more $$$$

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

here is a pic of the cylinder wall damage. all tubes/ electrical is disconected. looking for a hoist...

 

[Maxz695]

Re: 2001 mercury 150 EFI will not turn a full revolution

ouch. That is painful for anyone to look at!!

 

[Faztbullet]

Re: 2001 mercury 150 EFI will not turn a full revolution

That aint to bad and .020 might clean it up.

 

[coreymon]

Re: 2001 mercury 150 EFI will not turn a full revolution

thanks for the input. as far as i can tell the jury is still out on what the "smoking gun" is. the powerhead is removed and i will begin tear down soon. we will see...