Before I pull the motor out?

[mkingz]

125 Force L drive in an 89 bayliner. water in lower cylinder - compression check #1 - 155, #2 - 155, #3 - 160, #4 - 175. possible wet plugs in cyls 1 2 3 also. I was leaning towards head gasket but would like a second opinion or maybe some advice on how to trouble shoot a better diagnosis.

 

[pnwboat]

Either head gasket, exhaust cover gaskets, or cracked exhaust baffle plate would be the first things to check.

If the head gasket is not the culprit, then the exhaust cover gasket would be the next thing you should check. Be careful when removing the exhaust cover bolts. They're 1/4 X 20 bolts....not very strong and it's not uncommon to break a few off. They get kind of corroded and can be a pain to remove if you're not careful. If you do break a few off, it's not the end of the world. You can drill them out and replace them.

 

[tommarvin]

Like the man above, remove the head first, check for scoring of the cylinder walls, You will probably snap some bolts removing the head, you can drill them out yourself, but if you have never done it, let a shop do it if your boating budget is enough, It's better, and a lot less aggravation, to work OT if you can ,Don't go out to eat for awhile,cheaper bottle of cab or save for the shop.,
You have good compression, for a bad head gasket, IDK

 

[jerryjerry05]

You can have good compression and still have water from the head gasket..
​But with water on ALL the plugs I'd say the exhaust chest gaskets.

Like PNW said: the bolts are 1/4-20 and 3in long. On the regular motor they are 1in.
Start spraying with PB Blaster.
Use a small torch and start heating the bolts and tap with a hammer(tapping loosens the corrosion).
Spray and heat and repeat for a couple of days.
The extra length on the screws can make them harder to get out.(more surface area to corrode and seize)

Gotta wonder WHY?? the gasket/s blew??
Maybe an overheat?
Running on the hose without enough water?

Pull the head gasket and HOPE!!! that's the problem.
The PB Blaster and heat will help here too.

 

[mkingz]

I will start the loosening process today. This is best done with engine in place? Any reference to an online manual, instructions, diagrams, etc.?

little background: this boat was given to me by someone who didn't want to pay a shop to repair. my numbers for compression are off the $90 diagnosis invoice. the end result was that it would cost over 1K$ to open up and see what was wrong - head gasket was stated as "best case scenario" so I am hoping that is the issue. I have gas and diesel auto knowledge also have messed with 2 stroke stuff - dirt bikes, jet skis.........

bottom line - I have tools, not afraid to get dirty but I need some help with this one! lakes are real full here in NorCal this season and I want to get this boat up and running.

 

[mkingz]

all bolts came out with ease and the head is removed. no cylinder scoring and can't find any obvious trouble with head gasket or mating surfaces. since this was so easy to get to, would just putting a new gasket in and seeing if that was it be a good next step? would you re-use the new head gasket if it had to be taken apart again because the new gasket didn't fix the problem? where would you get it?

is this what I need?: [h=1]Head Gasket, 18-3857[/h]

[h=3]Mfr. Sierra[/h]

See Products $32.46 Replacement head gasket for Force 125hp outboards Replaces Mercury part number 27-824615 2 Similar Products Sierra Warranty Information Complete Sierra Catalog

sorry for all the questions but I have a bad habit of not asking for help until I have to fix what I broke and the original problem still. trying to get better about that. couple of more things: the lower bolts were wet and oily when removed and some water seeped out of head/block when bolts loosened. normal? thanks!

 

[pnwboat]

If you are having water intrusion problems in the bottom cylinder it would be normal to see some water come out of the bottom cylinder. Normally if everything is sealed up properly, you shouldn't see this happen.

Your link didn't post correctly, however, the description of the part looks to be correct.

Next thing to check would be the exhaust cover gaskets. There are two gaskets with a stainless steel baffle. The stainless steel baffle is usually warped from the exhaust heat but that's normal. As long as it is not cracked, it should be OK.

 

[jerryjerry05]

While your removing bolts and stuff?
Inspect as you go.​Remove the exhaust.

 

[mkingz]

got the exhaust bolts out, except for one. I can't get a socket over it. tried to clean around with pick and look at location with small dental mirror. bolt not centered in recessed area on manifold were bolt head seats. too close to upper side so even thinnest thin wall socket won't get around it.

2nd bolt down, right side (looking directly at it with output casting going right and down as if installed and upright), slightly in from bolts on either side - they would be #1 and #3 counting down form top right of bolt pattern.

any trick to getting at this one? due to limited recessed area closed and open ended wrenches will not get around it either. HELP!!!! one bolt did shear the head when turned but hopefully enough sticking out I can get at it with out having to drill it. this last one is the only one holding the manifold on - almost there!

 

[mkingz]

one more thing: two of the bottom three bolts came out with oil on them, left and middle ones. normal?

 

[jerryjerry05]

That just shows that something was leaking??
​The "oil" probably unburned gas/oil that filtered down.

You might have to remove the housing panel on that side.

 

[pnwboat]

I've had to "modify" sockets on occasion with my grinder to make them very thin wall sockets to get into tight places. That might work for you too. Depending on where the bolt is located, a modified deep well socket might work better than a standard length socket.

 

[mkingz]

You might have to remove the housing panel on that side.

housing panel?

I'm thinking that grinding off the head to the one remaining bolt is the way to go. I already sheared one so I will get one more when I order the gasket and any other parts I will need to rebuild, if only the head is missing I should have plenty left to work with getting the stud out judging by the thickness of the manifold and why ruin a the Socket if not necessary.

any reason to not go this route? sometimes easiest way isn't the best, I do have some cheap sockets around..........................

 

[pnwboat]

It's your choice as to whether to grind the head off or modify a socket. You're in a better position to make that judgement. Either way will work.

 

[jerryjerry05]

The housing panel to get more room??
If I remember there wasn't a lot of room in the engine compartment???
Yea cutting the head off might be an option.
Then be careful when trying to get the manifold off as using a pry bar can score the mating surfaces???

 

[mkingz]

No Title

Okay, hope you guys are still watching out for me. Had to back burner this project for a couple of days but I got it apart and am ready to buy some parts - I think?

I'd love to order up exhaust plate gasket set (2) and a head gasket and start reassembly but that's why I'm here, I'm not sure if I should do anything else. The exhaust plate (pic three?) got bent up a little but is completely intact, should I replace that? Another question is where do I find the engine numbers so I get the right stuff.

I'm ready to follow directions, just need a list of what to do and what to order. THANKS!

 

[jerryjerry05]

F695154 Plate gasket.You need 2
F476529-1 head gasket 1
E-bay is about the cheapest if you can find it there??

The plate is warped from the heat.
As long as there is no cracks?? it's ok.
I use OMC gasket sealer on the plate gaskets.
Nothing on the head gasket. In rare cases the gasket doesn't seal as good as it should(corrosion) then a silicone sealer is what I use.

 

[mkingz]

I could take better pictures of the plate if necessary. it seems to be in pretty good condition. I think most of the flexing is from removal, gaskets stuck on one side at bottom and the other side at top so half came with manifold and half stuck to block. otherwise okay so I will plan to reuse.

I will order the gaskets tonight as soon as I get home and get this back together next week. test run next weekend?!?!?

couldn't really see any clear failure point at any of the gasket surfaces. can we assume one of these three gaskets caused the failure? also one last Q, is there anything else I should inspect or replace as long as I'm this deep into it before reassembly?

thanks Jerry!

 

[jerryjerry05]

Just make sure the surfaces are clean and no gasket material is left.
.The plate when new was flat, then it got hot and warped. It will go right back when screwed down.