PD: Primary Drive Case Drain

[bmetcalf]

This is my version of the mod to be able to drain the primary case in a neater way than pulling the cover away from the engine. The screw for that spot has an o-ring and isn't tightened as much as the rest.

 

[Monkeypants]

Great idea, wish I had done that while the primary was apart last week.
I made a similar gouge to create a filler point for the clutch compartment.
That has worked well. Before that I used the " Fill the cover with ATF then slap it on" method.
Limited success with that. Very messy!

 

[bmetcalf]

Not my idea, Shriver told me about it 40+ years ago. But it is handy!

 

[Robert Watson]

I have 3 twins,
/2646 has a boss on the underside of the crankcase part of the primary, it has been drilled and tapped and has a plug fitted.
/166 has the boss but no hole or plug
/1997 also has the boss, and before engine assembly starts (soon I hope) it will also be drilled and fitted with a drain plug.

 

[Hugo Myatt]

I have 3 twins,
/2646 has a boss on the underside of the crankcase part of the primary, it has been drilled and tapped and has a plug fitted.
/166 has the boss but no hole or plug
/1997 also has the boss, and before engine assembly starts (soon I hope) it will also be drilled and fitted with a drain plug.

I believe the boss was intended for a drain plug but was not proceeded with as it was thought too vulnerable and likely to be swiped off by the nearest kerb.

 

[Michael Vane-Hunt]

Use a drain plug like this.

 

[Normski]

I use a large oil sucking syringe (made and sold for that purpose not a medical one) I’m fairly sure it gets nearly all out but just in case I change it every 1000 miles.

 

[Robert Watson]

That could be 5 or 6 times on a trip!

 

[Normski]

Or once a year

 

[greg brillus]

Primary chain will last far longer if you change the oil regularly.........the oil gets dirty rather quickly. I suck the old oil out as best I can with an old hand pump, then poke some good paper towel down the bottom to soak up the rest.