69 Bonneville extra oil return pipe mystery

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69 Bonneville extra oil return pipe mystery

Post by flexyourhead » Thu Sep 07, 2017 5:49 pm

Hi again. I have a real interesting problem/situation with my oil system and I'm hoping someone may have half an idea of what's going on. Here we go......
'69 Bonneville 650cc. The oil return pipe, rocker cover feed pipe and the engine oil feed pipe are all there and working fine. What I have is an extra pipe that runs from the underside of the motor, looking from above it is on the left hand side. It sits not far from the sump drain plug. It is located on the high side of the motors underside. ie. find the lowest point of the motor then run your hand along and eventually the case dips up, across and then down again to match up with the primary chain case.
I can't help feel this outlet has been added in but for what purpose, I have no idea.
When the motor runs, oil doesn't pump out of it but oil will ultimately come out. In fact I rode about 80k's with the hose disconnected with no issues other than a bit of oil coming out of it when I stopped.
Any ideas as to what it could be doing exactly?
Cheers in advance.

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Location: Cooma, NSW
Interests: Motorcycles & Choppers

Re: 69 Bonneville extra oil return pipe mystery

Post by Frostbite » Wed Jan 03, 2018 11:56 pm

If I didn't know any better it sounds to me like it could be the Engine Breather Pipe - ???

Check this link - it could be what you are looking for -- http://www.triumphrat.net/classic-vinta ... lle-2.html --

It is to do with the Crankcase Breather pipe that ran from under the engine up under the seat and a T junction out to the end of the rear fender .... - A lot of guys just put one of those small filter pods on them for convienience sake ....

Please, Do some more research though, to make doubly sure that IS the Oil Pipe in Question - OK ...

Don't just take my info for the gospel truth - All Care Given - NO Responsibility Taken - OK ...

Hope this Helps out ...

Cheers -
Greg (frostbite)
"Recomended Therapy - 2 Rides a Week Minimum" :D

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