Help water in oil honda BF25A

prowelder

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Joined
Dec 8, 2012
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2
I have begun a seal overhaul on my late 90'S Honda BF 25A outboard.This all started a few weeks ago when after pulling the dipstick the oil level had risen very high on the dip stick.After draining the oil I could tell it was thin very black no milky color.So I think gas got in the oil no strong smell though.. I still have some in a mason jar 2 months and no water separation still black.So cause could be either blow by or the can I have in the boat does not have a vented cap so in the sun light It may be pressuring up enough to have pushed fuel into the cylinders while sitting.I Installed a brass ball valve on the water separator problem fixed hopefully. So after a oil change and a long day on the water I check it again, now this time it is water light brown in color and water droplets as I drain this time.So I have decided to do a total engine gasket overhaul.I have not had this engine long and already did a overhaul on the lower unit seals.Started taking it all apart last sat so far I have broke 2 bolts one one head bolt 1 on the water jacket cover.The head bolt is still out far enough to get vice grips on it.The thermostat has been removed and was not there.Why would someone remove that?I have checked the head and top of the block for warpage using a starrett straight edge and feller gauge no gaps very flat so good there.So now to fix broke bolt issues.I will up date through the job.I am going to get the hole engine in the basement for cold weather is here and I don't have a warm shop.So hope to be set up to work in a few days.First question one of my service manuals shows applying sealant to both sides of the exhaust passage on the engine under case gasket and oil pan gasket.The next question I have is that it tells this in the section that is for the BF25d and BF30d I could not find the instruction for this step in the BF25A section of the manual so what is the difference between the A and D engines?Ma be I just over looked it? And further more why just seal around the exhaust ports and none of the rest on these gaskets?Any help on these issues would be great.
Thanks Matthew
 

hondon

Lieutenant Commander
Joined
Jun 11, 2001
Messages
1,922
Re: Help water in oil honda BF25A

There are some substansial differences between a 25a and 25d including some torque specs so be careful there.There is no sealant on the head gasket because it is already coated and those are torque to yeild fasteners,I hope you removed them as such.Seal all paper gaskets and tha oring on the exhast cover with the exception of the mani and carb gaskets.Get that bolt out before you go any further and inspect for damage.
 

prowelder

Recruit
Joined
Dec 8, 2012
Messages
2
Re: Help water in oil honda BF25A

Does anyone know for sure if a sealant is used between the block to case gasket and the oil pan gasket?
 
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