Mysterious Oil Leak

[Jim R]

I have a bottle of SAE 90 that has a tapered spout. I put it in right to the top. I just did a complete change of secondary gear oil. I also pulled the breather hose out of the starter cavity and blew through it. I couldn't tell if it was blocked but it definitely isn't now. Just drove a few miles through the gears. Going to wait for it to cool off and go check it again.

[chuck hahn]

What his question was is are you removing the bolt where it says something like " oil level " and filling just till it comes out that hole....or filling it to the top from the top filling hole???????

If till the top hole youre over filling it and expansion will force the oil to go somewhere.....and make a leak.

[Jim R]

Ah. No. I take the oil level screw out and fill from the fill hole on top and watch the oil come out of the hole where the oil level screw goes.

[chuck hahn]

had to ask...........

[Johno]

Guys,

I have exactly the same problem with my '81 1000G.

I have the stater motor cover off and there is grit and oil in the well.

Gave it a squirt with aerosol degreaser and getting a flow of oil and grit out the drain hole.

Not sure if engine or gear oil.

Could the oil come from the cam chain tensioner or oil pressure switch.

I had oil under the carbs.

Will try to clean it all up and find if the source.

Any advice appreciated.

[Brendan W]

If it's gear oil it will smell of cat pee. The main route for gear oil is through the vent hose although JIm R looks to have some sort of quantum tunneling going on.
If the tensioner and or pressure switch are leaking oil, it can end up almost any where back there. In fact a leaky tensioner can show at the front of the block on the ledge at the bottom of the chain tunnel.
The main culprit for engine oil in the starter cavity is the o ring seal at the sharp end of the starter motor.

[Brendan W]

Ah. No. I take the oil level screw out and fill from the fill hole on top and watch the oil come out of the hole where the oil level screw goes.

Thinking sideways here. When you open the filler is there an upper chamber that might also have the vent and could the pressure head of the upended oil bottle be enough to send some out the vent as you are filling ?

[Johno]

I have traced the leak to the oil pressure switch under the carbs.

The oil is running into the starter motor well and exiting via the drain hole.