C10 crankcase breather working?

[jacksdad]

Whilst sorting out all the snags on my newly rebuilt bike, I've spotted the elbow hose from the breather outlet to the bottom of the airbox isn't connected to the engine side.
I decided to give it all a clean, its then I noticed that there's no airflow/emissions from the breather: nothing!
I would think that the crankcase is venting through this 'tub' fitting on the top of the case, but nothing at all coming out. I've stuck my finger over the outlet 
But nothing! Is this correct? I'd expect to find a good gush of air coming out of the cases. In the past I've replaced PCV filters, or washed them out and replaced, after oil blew out of the dipstick hole!
Any answers please: I'm getting stressed as this bike gets ready to ride at last 

[Boomer]

The breather is just a cage full of metal mesh, so it may be clogged if you can't feel anything but it doesn't push a lot of air because there are 2 pairs of pistons going up and down 180 degrees apart. If you over fill the oil though, it comes out through there, which is what the elbow hose connecting to the airbox is for.

[connie_rider]

I agree with Boomer.
(Please don't tell anyone I sed that)

Ride safe, Ted

[VirginiaJim]

Hey Boomer!  Guess what!  LOL

[connie_rider]

"Virginia",,, Shhhhhhhhhh!!!! 

Ride safe, Ted

[jacksdad]

Quick update: my old motor has finally gone...expired, it is no more 😥
Went for a short ride and the oil light came on again, doing maybe 60 mph in top gear. I slowed down to walking speed and limped home, luckily not far. The engine rattled and banged for a few seconds, then the oil light went out and the noises stopped: not for long though!
Today I tried it again, started up, seemed to be all well, then it started belching out grey smoke from both exhausts. Shortly after the red light of death returned...so it seems to be very very terminal 😢
It looks like thrashing the old girl when low on oil was a very bad move.
So! Onwards and upwards, time to fit my 28k miles engine, how hard can an engine swap be? It's only held in by 4 bolts after all....

[dboogie2288]

Quick update: my old motor has finally gone...expired, it is no more 😥
Went for a short ride and the oil light came on again, doing maybe 60 mph in top gear. I slowed down to walking speed and limped home, luckily not far. The engine rattled and banged for a few seconds, then the oil light went out and the noises stopped: not for long though!
Today I tried it again, started up, seemed to be all well, then it started belching out grey smoke from both exhausts. Shortly after the red light of death returned...so it seems to be very very terminal 😢
It looks like thrashing the old girl when low on oil was a very bad move.
So! Onwards and upwards, time to fit my 28k miles engine, how hard can an engine swap be? It's only held in by 4 bolts after all....

Man that's rough...my 86 had an oil light pop on during a group ride in Ohio many moons ago. I stopped immediately and kinda freaked out. Ended up borrowing someones bike to finish the ride while they went 2 up, and then trailered the bike back to Indiana. Ended up being build up at the bottom of the crank case where the oil pressure sending unit resides. Some folks here said to blow it out with an air needle during an oil change....and sure enough, problem solved. I was going to regurgitate that same advice, but seems that would be no bueno here.

[Boomer]

That's a shame. Glad you got home safe though.
I use flushing oil every other oil change to prevent any build-up of such deposits.
When I was fixing Sanji's gearbox I saw some substantial crud build-ups so have flushed them regularly since then.

A clogged #3 big end oil way killed a friends engine https://gtr1000.com/graphics/gearbox/jesal.htm
On the image, I incorrectly wrote Main Bearing when it is in fact the Big End.

[connie_rider]

Boomer, explain what your using for "Flushing Oil"?

Ride safe, Ted

[Boomer]

I use Wynns but there are others on the market.
https://www.wynns.uk.com/product/engine-flush/

You add it to the engine oil, then run the engine at idle (DO NOT RIDE the bike) for about 15 mins.
Then drain the oil immediately whilst it's still hot.

The only caveat is that if you use it on an engine with a seal or gasket that is only sealing because of the build up of varnish, after using the flush that varnish will be gone and you will have an oil leak. 

[connie_rider]

Ok, thanx...

Ride safe, Ted

[dboogie2288]

Yeah if that's anything like the 'engine flushes' I've used in the past, it's just straight diesel. I used the motor medic engine flush, yep diesel. 5 bucks for a quart of diesel....seems like pretty good markup.

[Boomer]

Yeah if that's anything like the 'engine flushes' I've used in the past, it's just straight diesel. I used the motor medic engine flush, yep diesel. 5 bucks for a quart of diesel....seems like pretty good markup.

No idea. The ingredients are in the MSDS document that you can download. If that is the chemical composition of Diesel,... then it's Diesel. 
However, it works and works well. The amount of crud that comes out when I first use it on a new to me engine is considerable.

[jacksdad]

Hi there: quick update.
The bike is still running! When I ride at low engine revs, say max 5000 rpm, the oil light stays off, I did 40 miles over 2 days, just going out for short rides, and its sort of doing ok, just blowing grey/white smoke out of #3&4 exhaust. Not a huge amount, but its terminal this time..
Has anyone hit problems when swapping the engine? I've already undone the mounting bolts, not seized at all, so it should be a one day job...

[Boomer]

If the rear lower engine bolt slides out, then it's a 1 day job.
If it doesn't, well mine took me 3 days just to shift that one ****ing bolt!

You don't need to remove the swingarm, but you do need to disconnect the drive shaft from the engine.
When you remove the shaft, try to catch the little steel pin that pings out and put it in a ziploc bag with the circular spring it presses against.

Good luck. 

[jacksdad]

Hi, thanks for the replies: I've been sidelined with my usual health issues, now I'm back!
So, back to the engine. I've now undone the engine mounting blts and tapped them out a little, so thats good news, no seized bolts to worry about.
I've removed all the covers from the 'new' engine, the camshafts appear to be free from pits and visible wear/damage, the sump is very clean, as was the oil, and the filter again was very clean: The seller really did make a point of stopping me stripping the motor, he was adamant it is ready to fit, he'd seen it running and for once I'm going to trust the seller!
I did a few more miles on the old lump and I still love the ride...never give in!