Hi!, oil in a intake manifold, and crankcase breather hose crack

[foliver]

Hi!, how are you.
i'm working in my K75C 1986, after 6 years without use.
I've noticed, that the crankcase breather hose seems cracked, i assume this will have causes in the engine performance?
Second thing, today i've seen that one ( the one in the front of the bike) intake manifold, has some oil or grasy surface, not the others.
What can be the cause?
Last: i've the bike dismantled so may be is a good idea to change the intake manifolds, how i can see if they need repair?
Thanks!!

[The Mighty Gryphon]

Is that oil only on the outside of the intake manifold?  Is there any oil anywhere on the engine around it?  Could we be looking at the oil from a leaky fork seal?  If it was engine blowby, I would sort of expect it would be on the inside of the manifold.

[foliver]

Hello Mighty, the fork seals are bad, and I’ve the parts to change them, may be the cause…., and yes, there’s grease on the front of the engine in the same side of the manifold,so I guess you found the cause!
Very clever!

[The Mighty Gryphon]

Could also be a leaky brake line.  In any event, you will be taking care of the problem as you do your restoration.

[alabrew]

You should be able to tell what parts you need once you take it apart.
I ordered all 4 upper and lower parts to find I only needed one upper boot (split).
The parts that attach to the motor are $$$ and you probably don't need them as they are pretty stout.

[foliver]

Hello Alabrew, you are right, these parts are expensive...i think mines are ok. May be the rubbers? but seems to be fine, lets see.
I've just dismantled the water and oil pump, and found the 19 teeth shaft corroed, 180$......uf

Tomorrow for the first time, i'll attack the final drive lube. Seems easier than i thought, all the bolts, were at normal torque, and they unscrew easily, i like that.