Topic: lower crankcase tube unconnected

[agus]

Oil is going back to rear wheel, but have no idea where to connect a hose to.  Have checked the breath air cleaner but has nothing to do with this. The unconnected tube comes from rear lower cranckcase, just over the collar of rear fork assy.

The picture shows a view from rh side of the bike, and the tube is seen between the connections to the oil tank. Any help will be appreciated.

Agus.

[CycleRanger]

For what bike?

That tube connects to the back of the oil tank.

[MCRider]

Being that it has an oil tank, must be a CB750. Though it's always good to lay that out up front so there's no mistake.
CR is correct, the spigot down low at the rear of the engine coneects via rubber hose to the spigot on the lower inside of the oil tank.

What sometime happens is the PO will attach the upper vent from the cam cover to the lower spigot on the oil tank. They are different size hoses, yet it is done via a hose clamp.

Fix it and be happy!   

[MCRider]

The rubber hose from the cam cover is open to the atmosphere on ealry models, drapes over the air box and down towards the swingarm.

On later models it plugs into t he airboxitself.

[MCRider]

Very common mistake/omission.

[agus]

oh!!

have read somewhere that oil tank has a breather camera or so, and in my bike there is another unconnected tube on the inner part of the oil tank.  It's a cb 750 f2 /1978. Thanks a lot for your contribution.

Agus.

[MCRider]

oh!!

have read somewhere that oil tank has a breather camera or so, and in my bike there is another unconnected tube on the inner part of the oil tank.  It's a cb 750 f2 /1978. Thanks a lot for your contribution.

Agus.

That's later than my personal expertise. But conceptually, the lower crankcase spigot goes to the lower oil tank spigot. This feeds the chain oiler. But yours doesn't have a chain oiler, I think. So I may be off base. Or it may just be a dummy left over from previous designs.

All other breathers, on late model bikes, go to the airbox. I think.

[Hinomaru]

Agus, welcome to the forums.

No worries. For your 1978 750 F2: Just connect the hose from the rear crankcase fitting to the bottom oil tank fitting. (note the yellow circles)   





Once that oil line is properly re-connected, be sure and check the crankcase breather routing:

[agus]

Thanks a lot Hinomaru, you have a nice spare parts store!!!   
Both ends already connected, and tomorow I'll ride the bike.

Thank you all!!
Agus.