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Honda 2010 BF9.9 Head Gasket

J

JYY2100

New member
Hey guys second post here this forum has been very helpful. I recently got my hands on a 2010 Honda BF9.9 for a good deal. I have done a lot of work to it and it starts great now. one pull every time

However the guy I bought it from mentioned a possible head gasket problem. When I checked the oil it was cloudy and a quart too high which leads me to believe water is getting in from somewhere.

Before I dive deep into changing it I was curious if there were other things it could be ?

Also is it a difficult job ? I have done head gaskets on cars prior so not to concerned but just am curious on what I’m up against

Thanks in advanced
 
Well.
It's universally known that a thermostat that is stuck open can and will cause an overly rich condition and poor combustion along with lowered operating temperature. There is a phrase....
..."making oil" that stems from that because the oil level will increase because of it.

BUT...it's typically more from unburned fuel vapor and not so much condensation.

The ones I've seen like that the oil smells like gasoline and remains black. I certainly haven't seen it all though.

Also, a QUART overfull???
Are you positive about that?

Could it just be he overfilled it?
That happens all the time.

If it truly IS a quart over AND it's water, then yes, I would suspect intrusion but from where I can't say.
Never seen that on a twin cylinder. I'm sure it probably happens though.

You should drain the crankcase into a clear container or two. Give it time to sit. Separation of the oil and water might give you a more accurate picture of what and how much is in there.
 
Also, you could cut the oil filter can open and spread the media out to get an idea of what may be happening including possible engine damage (sparkles)

The item below from Amazon makes that chore a little easier

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jgmo, appreciate the input again, I didn’t measure the oil but it was very high on the dip stick like 2-3” above the full mark so you’re right I stand corrected. I’m hoping like you said the previous owner over filled it though

I tested the thermostat seems to be working ok but doesn’t hurt to change so I’ll do that.

The motor seems to run great, I think I will flush the oil until it reads clear. Change the thermostat like suggested and take it to the lake to see if the problem occurs

I’ll give an update once I do so, thanks
 
Well, if the Tstat tested ok it probably doesn't need to be replaced. Your call.

It's GREAT that you looked at it though!

I've seen, so many times. that there wouldn't even be one in there!

People take them out trying to solve a problem. When, not knowing that, an engine without one can overheat EASIER because the bypass circuit (reheat/fast warm up) doesn't get closed off after the engine reaches operating temperature. As a result, MAXIMUM COOLING can NEVER be achieved!

So....it becomes a "fix" that can just make things worse.

Goodonya for checking it out.
 
Wow learned something new, I just know there a crucial part of an engine in general so I figured to test it

I’ll hopefully have the boat out within the next couple weeks though to give an update. We’ll see how it goes lol
 
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