leak test - oil in crankcase?

[Adamnb1]

Hi - 98' KDX 220
I made a leak down tester ($15 ) and did a test yesterday with 6psi. It held great and didn't have a noticeable drop after even 30min.
However, there was a bit of oil sloooowly squeezing out from a spot in the case.. behind the stator plate under the crank shaft. (see pic below)

This oil seems to have the consistency of transmission oil.. This would pretty much suggest that either my right crank seal is sucking oil, or the crankcase centre seal is bad - is that correct?
Could the oil that's coming out simply be pooled gas/oil mixture? My only obvious problem with that is that it seems far to thick to be gas/oil mix....unless somehow the gas left the mixture and just mostly 2 stroke oil remains.
What do you guys think..

[kdx633]

porous casting.The kdx is known for for this problem specificly.Fredette even mentions this in one of his maintenance vids.Clean the area with a strong solvent and use a jb weld type product to fill in.I used devcon two part titanium putty cuz that's what I had and have not had a problem since.

[Adamnb1]

Thanks - I have already fixed the leak with JB weld, and at this point I'm just wondering about the questions I had in the second paragraph.

[adam728]

In the crankcase is basically just premix oil, very little fuel remains behind.

The fuel atomizes as it leaves the carb and makes it's way through the engine. The premix oil falls from suspension with it and most deposits in the lower end, coating bearings and being flung around by the crank and rod into the piston/cylinder.

[Tedh98]

I don't think your seal is leaking. I say that only because I don't see a trail of oil coming down from the seal.

This is what my leaking seal looked like:

[Adamnb1]

thanks adam728, I learned something new!
Ted, I know where the oil is coming out (the casting), I was speculating about how transmission oil might enter the crankcase (from right crank seal or crankcase mating seal).
I think adam728 is correct and what I'm seeing is just premix (I didn't realize that the oil separated from the gas like he described).

Seeing this casting leak, it makes me want to pop off the RHS cover and look for more leaks!

[KDXsg]

Hi, I have got similar problem and had fill up the tiny leak with JB weld. Upon testing using DIY leak test kit, at 6 PSI the pressure would drop to 5psi in 5mins.
It took another 5mins to drop to 4psi. But at 4psi the drop is very minor. Can i still run this engine? or I risk leaning sized? thank you for any advise.

[adam728]

Hi, I have got similar problem and had fill up the tiny leak with JB weld. Upon testing using DIY leak test kit, at 6 PSI the pressure would drop to 5psi in 5mins.
It took another 5mins to drop to 4psi. But at 4psi the drop is very minor. Can i still run this engine? or I risk leaning sized? thank you for any advise.

You'll probably hear other opinions, but if it were mine I'd run it. Especially if it were a new build, as the base gaskets are well known for "breathing" until fairly wetted out from gas / oil.