Topic: CB360 smoking breather tube

[Joshrma]

I just swapped the "spare" engine onto a '74 CB360.  Got it running, but once heated up, it smokes from the breather tube.

It had obviously been sitting a long time, and I had to swap out the clutch, as it had been sitting dry in the sump so long that it was junk. I cleaned plenty of rusty particulate out of the sump, although nothing sludgy, FWIW.

It has compression, doesn't burn oil out the pipes that I can see, and idles smoothly, but as soon as it gets up to temperature, it begins to puff oil smoke from the breather tube, and tends to stall at idle, which I'm guessing is a top-end lubrication issue.

From the messy liquid gasket job and mashed housing screws, I can see that I'm not that first guy here, and that whoever was here first was less competent than the low bar that I hold myself to.

Knowing that the CB360 lubrication system isn't great and that this is the longest-dormant engine I've worked on, I'm looking for advice:

At the moment the plan is to order gaskets and an oil cup/filter wrench, check out the oil pump, clean off the surfaces (hoping I find obvious blockages with liquid gasket), snake the passages with guitar string, and hope that does the trick.  Anyone got additions, thoughts or a better plan of attack? 

[tshrey]

My 550 does that, a little visible smoke (I'm just venting it through a small filter).  I figured that would be rather normal to have some vapor considering how the oil is getting thrashed around by the cam and rockers.

[TwoTired]

Color of "smoke" is important to consider.
White is usually water vapor.  Any condensate inside the motor will turn to vapor as the motor casing heats up.  It will do this until the engine has been at operating temp for 20-30 minutes or until the water has all boiled off.  Outside air temp and humidity can also effect this duration as it is an air cooled motor.

Blue smoke is usually oil vapor.    And warming up the engine doesn't have much effect on this from the engine breather.

If the smoke is persistent, you may wish to do a leak down test.  Listening to the air leakage can tell you what in the engine isn't sealing like it should.  Rings, valves, or...

You haven't overfilled the oil sump have you?