F100 oil pan gasket

[GrilseFish]

So in an attempt to solve a water in the crankcase issue, I've removed the powerhead, gasket and oil pump. Other than the power head, is there any other area where the cooling water and engine oil might combine? From looking at the manuals, there does not appear to be. But as I'm not an outboard mechanic on regular basis, I don't want to tear down the rest of oil pan, etc. if it's not necessary.

thanks,
Jeff

[boscoe99]

Head gasket or exhaust outer cover are possibilities

[rodbolt17]

warped oil pan is possible as well.
especially if its ever been overheated.

[GrilseFish]

For the moment, I'm ruling out the headgasket. A leakdown test revealed nothing, sparkplugs all look normal. I have replaced the upper exhaust gasket, the one on the side of the powerhead.

My big question is whether or not to dig deeper into the oil pan, etc. I see there's an exhaust manifold and gasket on the very lower end of it, would that be a possible leak area?

The motor has never overheated, I'm the original owner. But I guess I can pull off the shroud on that area and check.

thanks,
Jeff

[fairdeal]

you pulled off the engine -

the casting directly under it is the "exhaust guide"

Rodbolt's saying to check under THAT where it mates with the oil pan

of course the upper motor mounts have to come off...

[rodbolt17]

lower pan,upper mounts,lower mounts,lower unit all have to be removed to disassemble the midsection to access the oil pan.

[GrilseFish]

Thanks for the help, this is turning into a larger project than I thought. I was able to figure out how to get the mounts loose and remove the exhaust guide and oil pan like I knew what I was doing...putting it back together, now that's a whole other story.

Jeff

[GrilseFish]

Okay, so I guess I still need to separate the exhaust guide/oil pan from the upper housing. I've removed the four bolts, nothing else left. Any tips on separating these? Besides not prying with a screwdriver? I'm following the steps in the Yamaha manual, this is where I'm stuck, literally.

thanks,
Jeff

[rodbolt17]

best I recall, mind you I have not had one of the antiques apart in a few years.

you have to completely remove the midsection (upper casing) from the steering bracket.

then you can disassemble the oil pan.

[GrilseFish]

Hey! who you callin' an antique? Just kidding, thanks for the help. I've gotten the whole casing off, and now I'm working on taking off the muffler and the pan. But I've broken at least one bolt, I'm soaking the others to try and avoid.

This motor is only 17 years old, I thought it had to be at least 20 to be considered an antique...

[rodbolt17]

my youngest kid is an antique.
broken bolts are part of this.
bullit point drill bits are your friend.

carefully check each gasket surface with a straight edge and feeler.

anything more than .004" is reason to fix or scrap that part.