There is two oil drain plugs?

[jaybar6]

Oh no guys! We forgot about the clutch housing. There is contaminated oil in the clutch chamber. The clutch and primary drive is filled with oil through a hole in the gearbox chamber. Which is lower than the engine ridge. So is filled before the engine.
So to completely remove all the old oil, one needs to remove the clutch casing as well as both sump plugs. jay

 

[cra-z1]

Looks like you will be splitting the cases at every oil change to get all the oil out.

 

[JJames]

Looks like you will be splitting the cases at every oil change to get all the oil out.

Yes. The bearings will retain some old oil so I always replace them.

 

[jaybar6]

Yes. The bearings will retain some old oil so I always replace them.

Always good to have a deep cleanse now and then. lol

 

[jaybar6]

come to think about it. that oil in the gearbox and clutch has been in there for 40 years. if one has only been changing the engine oil. jay

 

[Kevin Werner]

come to think about it. that oil in the gearbox and clutch has been in there for 40 years. if one has only been changing the engine oil. jay

When I drained my "Red Bike" the first time it was apperant that the 'other" drain plug had never been removed. 17003 miles.

 

[grokdeep]

What size are the drain bolts. I thought they were 27mm but they are larger than that.

 

[member43148]

Those are 27mm .
If those have been abused with say a large crescent wrench which can distort the hex shape, that hex may no longer fit a 27mm hex until the shape of the drain plug is restored with a file ?

 

[JJames]

What size are the drain bolts. I thought they were 27mm but they are larger than that.

Drain bolts are 27mm.