86 merc 3.0..water in oil....checking parts, whats next?????

[p12]

I've begun checking parts, figure i'll run it by you all before i dig deeper into the wallet.<br /><br />I've got an 86 Sylvan V171 (w/140 Merc I/O with an alpha one gen 1 drive) from my dad last year (2004), he was the original owner.<br /><br />He sat the boat outside uncovered, including exposed engine due to broken cover, in 1998....so for over 5 years the boat sat outside in Kentucky exposed to the elements. (note: snow on floor of boat at bottom of pic) ...claims he winterized it as he had the previous 11 winters.<br /><br />The history of this chocolate shaked oil is:<br /><br />

• <br />
• Get boat, get running (somewhat), then find milky oil <br />
• Check freeze/casting plugs... no dimples, not pushed out<br />
• flush w/kerosene, change oil/filter, run engine, oil looks good, check next morning, ...milky <br />
• pull manifold and riser, pressure test manifold-good, visually inspect riser, looks good<br />
• reinstall hoping it's riser gasket,<br />
• change oil/filter, run (on starter fluid), oil looks good, check next morning, ...milky <br />

<br /> <br /> So I figure due to being exposed to elements so long or due to poor winterizing, block is cracked....but before i pull the engine and prepare for a $900 repair/replace bill, is there anything else i should look for???/<br /><br />..or better.. What is the next step?<br /><br />Thanks for your time.<br /><br />Mike

 

[jeff13601]

Re: 86 merc 3.0..water in oil....checking parts, whats next?????

You might have a bad head gasket. Before you just scrap the motor, do a compression test and a pressure test on the engine. If this doesnt show anything pull the head and look for cracks. Although it wasnt taken care of well if it was winterized the block shouldnt be cracked. Its probably running rough because the carb is varnished up. A pull and clean will do wonders. I have the 22 foot sylvan

 

[p12]

Re: 86 merc 3.0..water in oil....checking parts, whats next?????

Yeah, The carb will defenitely require a rebuild when the engine gets sorted out.

 

[p12]

Re: 86 merc 3.0..water in oil....checking parts, whats next?????

checked the compression, <br /><br />cyl psi<br /><br />1 165<br />2 165<br />3 135<br />4 165<br /><br />#3 spark plug looked a bit rusty.<br /><br />Thoughts????, ideas???

 

[jeff13601]

Re: 86 merc 3.0..water in oil....checking parts, whats next?????

You are going to have to get the block preassurized and look for the leak. If not you are going to have to pull the head and look for the crack. The rust on the plug could be from snow blowing in the carb