ET: Engine (Twin) Oil Leak

nigsey

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Nigel, When you pulled the primary case away a nats, To drain the oil,
Did you first loosen the Primary chain ?,
Because the tension blade pivot is slotted half in the outer case and half in the Crank case,
You may have had enough to get the oil out, But just check the chain tension,
You don't want the chain too tight, It can upset the clutch.
Cheers bill.
Many thanks Bill, yet another thing I was unaware of, I’m on such a steep learning curve but loving it, everyone on the forum very helpful and patient! Yes, enough of a gap to drain the oil, the case went back ok including the original gasket and so far no leaks from the joint. Checked the chain tension before running it and it was fine.
 

Bill Thomas

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Well done, If you ever take the clutch and primary case off, It's best to loosen the chain first.
As when you put it back on the you have to locate the rear tensioner pivot in the outer cover,
easy enough as long as you know about it.
Good Luck, Bill.
 

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nigsey

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VOC Member
Well done, If you ever take the clutch and primary case off, It's best to loosen the chain first.
As when you put it back on the you have to locate the rear tensioner pivot in the outer cover,
easy enough as long as you know about it.
Good Luck, Bill.
Many thanks Bill, I’ll remember that.
 

Chris Launders

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Not exactly subtle, mine is JUST visible exiting under the footrest mount in the first picture and the black plastic pipe going down the back of the rear footrest plate in the 2nd.

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nigsey

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Not exactly subtle, mine is JUST visible exiting under the footrest mount in the first picture and the black plastic pipe going down the back of the rear footrest plate in the 2nd.

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Well I’d say that’s quite subtle actually. Great how owners come up with their own designs and solutions. I’m hoping to get away without a breather but we’ll see. My bike was restored in 2009 but not by me, it’s covered 11k miles presumably without a chaincase breather. Perhaps it was something I did that caused the leak but time will tell.
 

Bill Thomas

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As I said , The standard bike Primary case, Breathes through the gap behind the dynamo,
Sometimes too much ! , leaking oil out,
But My Twin Special which has done more miles and had a very hard life is fine as standard,
Don't know why !.
It's when we seal them up other things can happen ?.

Sorry, Looks like I am Drunk :D
 

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greg brillus

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On my big capacity single racer I ran an automotive type PCV valve in the breather line (a 1/2" bore pipe coming from the generator hole) up and to the catch tank at the back of the bike........after a race session the oil had been pumping out of the rear pushrod tube lower seals ( "O" rings) to my utter surprise......Such was the pressure build up in the crank case from that PVC valve...... Since put a good shield around the breather outlet and running a reed type valve instead.........So if you blank off something, then you might just spring a leak somewhere else.........I've found if the primary oil level is kept within limits, it does not loose any oil out the genny hole........If the primary is filling up, then perhaps you need to check the engine breather and revise it if necessary.
 

Bill Thomas

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My ex L/ning never fills up the case, Just makes a mess after I have stopped,
A little bit of oil , Can make a BIG MESS.
I always check all my levels before a ride.
 

Chris Launders

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VOC Member
Well I’d say that’s quite subtle actually. Great how owners come up with their own designs and solutions. I’m hoping to get away without a breather but we’ll see. My bike was restored in 2009 but not by me, it’s covered 11k miles presumably without a chaincase breather. Perhaps it was something I did that caused the leak but time will tell.
Nigsey, When I said not exactly subtle I was referring to the picture Cyborg posted earlier with the sprocket cover with a fitting in the middle sticking straight out.
 
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