Runs great, but needs crank seals apparently...

[svracerjosh2]

Hi All,
Just got the old KDX going again after many years. (2000 220r) I've had it out a few times now, it runs really well but clearly leaking a bit of transmission fluid into the chamber (some consumption and black goo dripping out of the muffler).
Overall hours are very low, so I'm guessing it's mostly deteriorating seals after 25 yrs, not worn out metal.

Assuming that to be the case... I'll get a manual, gasket kit, good oil seals, and go about disassembling the whole thing. And obviously inspect /replace anything else that is looking iffy once in there.

(Apologies if this has been asked 100 times, but) What other parts would you likely replace once the cases are split? I am (for now) assuming bearings, crank, piston and all that are 'pretty much like new', so hopefully it can just go back together. I'm thinking more about wear items. RIngs, maybe?

Thanks for any pointers!
Josh

[bufftester]

That black goo is known as Spooge and is normal for these bikes to varying degrees. Linked to the type of gas and oil you run as well as the mix ratio, in addition to a bunch of other things. Crank seals will result in lean running issues and oftentimes premix under the flywheel cover.

[KDXGarage]

I would do a pressure and vacuum test before tearing it all apart.