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BF100 Water in engine oil – Please Help

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baggerman

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I am new to forum. Just purchased older 1981, I think. Serial # is B100S 1302665. Dealer says model is a BF100B SA made in 1981. Motor has not been run in at least 10 years. Motor looks very good for age. Got it home and put motor in large bucket of water and it idled good, pees good, forward and reverse work fine. Gear oil when drained looked good - no water. Drained oil from motor and it was extremely milky, clearly water in oil. Hoping it was just condensation over the years of non-use, I refilled with oil ran motor 30 minutes and drained motor oil and again extremely milky. Refilled it again this time only running motor for 5 minutes and got the same results – extremely milky. Did compression test and both cylinders came back at 130 psi. Where should I start? Please help - Ordered Manual published by Honda from Amazon today.
 
The wide open throttle should be approximately 151 psi. Most likely, you have not opened the throttle all the way....you would have to put the motor in gear to get it to wide open throttle, due to the limit that you mentioned. So, you are probably ok on the compression.

This may sound crazy, but since it runs good, most likely the water is not getting into the oil through the head/head gasket.

The most likely thing to be the problem is a warped oil fill and/or failed oil fill o ring. See parts 13 and 14 http://www.boats.net/parts/search/H...A/OIL PUMP OIL FILTER EXHAUST PIPE/parts.html

Unfortunately, you have to remove the powerhead to get the bolts out, unless you drill holes in the side of the engine cover.

Mike
 
AND, while you have the engine out, take this excellent opportunity to:

Clean or replace the oil "filter" and clean the sump and lower end.

Check the wear on crank thrust, mains and rod bearings. Now's the time to replace them if funds allow although, not expensive and not hard to do.

Check wear on the oil pump.

You will be replacing the sump gasket. Make sure to order a new oring for water passage through oil case to block. This is the other place water can intrude oil besides the oil fill hondadude pointed out.

Watch out for "hidden" bolt holding oil case to block. Since you will have the manual, they show you where it is and it shouldn't be a problem.

These little twins are rough and tough and pretty easy to work on. Sounds to me like you may have found yourself a good one.

Good luck and remember we are all here rooting for you.

Let us know how it's progressing, ask more questions or post pictures of your new to you baby.

Welcome aboard!
 
Thank you so much Hondadude and jgmo for your timely replies. You guys are quite the tandem team. As a prior guest I have noticed that you guys and other outstanding members have saved other members several thousands of dollars with your expert advice. That’s why I joined this forum.

Back to my problem - Compression check was done with 6 pulls on the rope by myself in forward gear with throttle wide open and both plugs removed, gas supply disconnected and carb out of gas, but the motor was (from earlier post) not in bucket of water that may have affected the psi readings. Are you still thinking head or head gasket is OK? Maybe I should have done 10 pulls or more.

Hondadude thank you for the link. I understand the possible warped oil filler body shown as part #13. Is the o ring that you mentioned part of the oil filler gasket as shown in part # 14?

Jgmo thanks for the additional information. Excellent advice – Thank you both again, waiting for manual to arrive before I tackle pulling powerhead.
 
Hello Mike,

Got the manual and have removed powerhead. I've hopefully attached a picture that concerns me. This picture shows a large cutout with jagged edges just below the oil filler housing. I'm guessing this is not a factory cutout. If this is a factory design - great. If not is this the problem with substantial water in the oil.
Thanks for any help you can give me.

baggerman
 
Hi,
Your pic didn't load I guess. I'm wondering if you've probed the bottom of the oil case for any pieces from the jagged hole?

I don't believe that area of the block is critically structural so with the power head off, you can probably do an effective repair, especially if you have the portion that cracked off.

If the missing metal is the result of salt water corrosion, it can probably still be repaired or you may be able to find a replacement block through the purchase of a not running parts motor.

There are hundreds and hundreds of these outboards out there.

Hopefully you can get the photo loaded.

Don't give up! She runs good, RIGHT? You can get her straightened out as long as you don't get discouraged.
 
I agree with Jimmy on what he says. Hopefully, you get the picture loaded.

To answer your question from a couple of posts ago....the o ring is the rubber gasket that you see in the picture. The part of the gasket where you see an actual "o", is where the water passes through.

Mike
 
HondaBF100.jpgOk Guys,
I’ve finally got the pic uploaded, hopefully the resolutions is good enough for you to see my concerns. There are two cavities that have jagged edges located just below the oil filler body. The larger one is fairly obvious but the other cavity with jagged edges is further north on the pic and is a little harder to see. After reviewing the pic, please let me know if my engine is DOA.
Mike - Thank you for giving me a headups that the O ring being part of the gasket as you pointed out on the link by part number 14 – very helpful.
jgmp - Thank you for the encouragement and also keep the faith. If the engine is still alive, you mentioned an o ring and gasket. Any chance you can you show me the parts # by a diagram?
Thank You both Very Much
baggerman
 
Do not worry about those casting " imperfections "----If those were a concern the motor would have blown up many years ago.----It is a 1980's motor after all.
 
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OK Guy, I uploaded another pic that better shows the other smaller cavity with jagged edges. Please let me know if this is Ok - Thanks Baggerman
 

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I agree with racerone....casting imperfections like that are perfectly normal. Nothing there to worry about AND the water passage looks almost NEW! No corrosion whatsoever!

I doubt that this outboard has a ton of hours on it. Either that, or, it was taken well care of and regularly flushed. I still think you got yourself a GOOD ONE!

In the link below, is the little oring you need to ensure a good seal for the water to pass from case to block. It is item #33. You will see, when you get your new "oil pan" gasket, that there is a small "cutaway" circle, within the boundary of the gasket, that the oring nestles in to seal the water passage through case and block.

But, because my NEW $800 phone can't copy and paste like my $150 phone (sheesh) you will need to copy and paste the whole URL as opposed to just clicking on the blue part.


http://www.boats.net/parts/search/Honda/Outboard Engine/0/BF8AH LA/ENGINE COVER (2)/parts.html

So far.....so GOOD!
 
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Whoa! Now I can see what you were saying! That does NOT look wonderful. I will have stare at it for a bit to get oriented and decide what may have happened there!
I'll get back to you a.s.a.I.c.
 
I'm thinking that the part in question is the oil filter "flange" As Honda calls it. Why it would "chunk out" like that is anybody's guess.
It may have suffered an oil pump failure. We tech's call that a "grenade job".
The only thing to do is to pull the flange and oil pump and inspect. Look for pieces of metal.
 
Yes.
But I think that broken piece is the pickup flange. It's hard for me to tell. The pressure relief valve may have stuck and caused "a problem."
 
Not sure that I am seeing anything wrong...other than casting issues.

Here is a shot of a BF8A, which is made just like the BF100.
 

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Can't open your second pic Mike. But, comparing your 8hp to his 10,
There looks like a protrusion the 10 has that the 8 doesn't. And, it looks like there is a hole in that protrusion. At least to me anyway. But the "dimple" in the corner of his oil pickup flange looks like it has a hole in it.

Help! I'm seeing holes everywhere!

Or, is that just black, stuck on carbon dust???.

I might have to go open up one of my junker motors to actually form an opinion as to what I'm seeing.
 
Jimmy, I posted the same picture twice. The second comes out better full screen. The post that I made that says here is another picdture....does not have a picture.

I agree with you on what looks like small holes in the pickup flange. That is where baggerman is going to have to check. It does not appear that there should be holes there. It does not seem that those holes would be the source of water in the oil, since it is located in the oil sump. It could possibly lower the oil pressure.

The jagged round area may just be a casting flaw....as long as there is no hole in that area. In my picture, there is a very slight raised round area in that same spot...without the jagged edges.

baggerman....the oil fill in some of the older motors was plastic and they warped. If you check all of the holes, etc that we are looking at and all looks ok....after all the debate and conjecturing, I would order a new oil fill as well as the o ring/gasket unless are are absolutely sure that the oil fill has no warp age especially in the area of the water passage.

Mike
 
Ok Guys, I loved the debate and conjecturing – YOU GUYS ARE GREAT!
Just to let jgmp know he is correct there is a hole in the pickup flange shown in the 2[SUP]nd[/SUP] picture I uploaded. The entire black area is part of the hole; it is not black stuck on carbon dust. The hole measures approx - ½”x1.5”. Looking in the hole, I think I can see part of the crankshaft. Maybe this hole provides oil to or from the crankshaft. Does that make any sense?
Mike, I will be ordering a new oil filler housing because I’m not certain the plastic one is not warped - ordering gasket with O ring embedded as well. And as jgmp suggested I will be ordering a new oil pan gasket and the O ring.
A few more questions if you guys don’t mind.
About the oil filler housing – I see it has 3 hoses connected to it. I know about the waterline hose thanks to Mike’s earlier reply. I can see that both of these hoses connect at the other ends to the bottom of a canister located within the flywheel housing, what function does the canister have?
Manual states that when starting assembly of extension case it calls to apply liquid sealer to the mating surface before assembly. What does liquid sealer mean – Silicone or something else?
This motor has a Serial # of B100S 1302665. One Dealer thought that the serial # indicates that the motor has model # of BF100B SA made in 1981. Is there any way to confirm the Dealer is correct?
Thanks Guys Again for all your help - baggerman
 
Because the engine is laying down or "sideways" the oil case holds the oil and the conventional oil pan is just a cover for the crankshaft.
Some call this a "dry sump" although it still holds the end seals.

The hole we see may be an oil drain back hole with jagged edges. But, if you think it may be there because something came loose and punched it out, you will need to pull the oil pan and investigate. If you decide to do so, you should hold off ordering parts until you look things over in there. At the least you'll need that gasket to go back together anyway.

While you're in the sump, you have an opportunity to inspect the main and rod bearings if you want.

I hope that is just a drain back hole.

The canister you asked about is the filter holder for the crankcase ventilation system.
 
Thank You jgmo for your quick reply - If I amnot mistaken the engine is not on it side but just upside down. Does thatmake sense from your perspective? Thanks for the info on the canister.I'm hoping the hole is just a drain back hole to the oil pan. Againthank you - baggerman
 
Mike,
Thank you for confirming the model number and year. I'm still thinking about what jgmo said about looking at the main rod and bearings. I'm not sure exactly where those are located on this powerhead, but I'll try to figure it out before I order parts.

baggerman
 
You just need to determine, as best as you can, that the hole is, indeed, intended to be there and that nothing came loose and punched it out.

You've already said that the engine seems to run well and all this was started because of the water intrusion. I mean, most engines don't typically run very good after things come loose and pieces punch holes in other pieces.

But, it would be a shame if you have it torn down this far and missed the fact that you should have gone another step, removing the sump pan, and checking the "guts" of the engine.

To answer your question about the engine's orientation; no, it is not upside down. It is actually laid over backward when compared to, say, a race car engine. The cylinder head on your outboard is at the back of the case with the spark plugs pointing to the rear as well. You can imagine the top of the piston traveling toward the rear and then toward the front of the boat in a horizontal, reciprocating motion.

Conversely, the "right side up" race car engine has the head on top of the block, the spark plugs pointing skyward and the piston traveling up and down.

It's a small point really but, the more you know, the better off you'll be as you learn the mechanics of the outboard.
 
OK Guys, I’m back
Ordered parts and installed new oil filler housing with gasket and new oil pan gasket with O-ring. Installed powerhead and ran engine at idle for 10 minutes drained the fresh oil and just guess at best approximately 95% of the water that was in the oil is now gone. Put fresh oil back in engine and this time ran engine 30 minutes hoping that the 5% water was just left over and needed to be flushed out. I got the same results. Repeated the process one more time but this time ran engine 1 hour - Got same results. The thermostat has not been changed in years, could that be a cause of small amounts of water to get into the oil? Also after running engine for 15 minutes or so the cylinder head is very warm. I can touch it for about 4 seconds before it becomes too hot. Is that normal? Again Thank You for your help - baggerman
 
Well, first off....congratulations on putting her back together and having her run ok!

Are you saying that you didn't replace the tstat? Or, are you running without one?

You shouldn't be able to hold your hand on the head constantly but you very well could be experiencing elevated head temp if there is still an issue with internal flow. Kinda hard to tell from here.

It does sound as if you still have an internal leak. Even with a stuck open stat you wouldn't get condensate build up in the crankcase that quickly.

Did you pull the valve cover off and clean the "goop" out that was there from the initial contamination? That's the only area that would "hold over" that much contaminated oil and moisture.
 
I have not looked at the tstat so I don't know if there is one there or not - so I should most certainly take a look. No I did not pull the valve cover and clean any goop that may be there. And by the way - Thanks for helping me learn more about the mechanics of an outboard.

baggerman
 
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