Oil Seepage….Normal?

[Lambchopz]

Hello friends,

The bike in question is a 75 Yamaha RD 350.

As stated, have noticed a light film of oil forming on the inner case below the generator.

There will usually be a drip forming below when the side case cover is assembled.

Have done a leak down test and it passed with flying colors.

The seals on the transmission side show no sign of wetness and no oil film on that side of of the case.

Bike runs on pre mix @ 32:1.

Is this a cause for concern? Sign of future seal failure perhaps?

Not sure, so I wanted to ask the experts,

Any help/ feedback would be appreciated.

[Striker1423]

It should stay dry. Left crank seal would be suspect to me.

Did you over-oil the points wipers?

[m in sc]

agree. LH crank seal going.

[Lambchopz]

Thank you. Very much appreciated.

[SUPERTUNE]

Has the engine been rebuilt with a new crank rebuild?
When main bearings get old and loose they let the crank seals leak at speed...
Chuck