Lotsa Oil From Breather Tubes?

[OakBehringer]

Take a look at this pic. This was taken a few minutes after turning of my '73 which has two breather tubes running down the backbone and the back of the engine (stock). This is typical. It's oil, and it's coming from said breather tubes. It seems like a lot to me, and I suspect that it's pissing like this as it runs. What could this indicate? Eh, doesn't make much sense to me, the breather at the top of the motor is nothing more than a few layers of perforated steel in a box, right? Doesn't seem like that could be malfunctioning, and I can't imagine what would cause excessive oil to be near the breather.

Thanks,
Adam

 

[bluebikerblan]

No pic Oak? Oil level now or recently too high? Reduce level... as it will accumulate then puke it out after setting a spell on the restart.

Just checking here and don't want to offend but; Many, if not most of us ride around with too much oil put in, for one reason or another. Not level on the center stand....dipstick not just resting on the threads (as opposed to screwed in to measure)...oil added to full line (as opposed to just between the two marks).

Usually that's the cause of the 'puking'...that's all it can do and about the only place (in normal circumstances) it can go. Clean out the lines, reduce to lower level and see if it doesn't stop/slow down. Blue

 

[OakBehringer]

Forgot the pic, it's there now.

Not offended at all. I don't have a center stand, but I'm holding it level when I check, and not screwing the stick in when I check (that would result in too little oil as opposed to too much, anyway). According to my stick I'm not filling it up too high, it's right in the center of the acceptable range. I seem to be losing it quick, too, and I think this is why. I'm not smoking and this is the only major drip.

 

[bluebikerblan]

Real interesting discussion on this subject re early XS's, oil levels and recommended amounts of oil here:

http://www.xs650.com/forum/showthread.php?t=1321 and also....

http://thexscafedotcom.wordpress.com/2011/01/26/xs650-dipsticks/

XS John and Shell Thuet had some interesting observations, beliefs and practices didn't they?

Here's my take after reading all this....Up til the 75B Yamaha was recommending (and the dipstick would indicate for) putting
3000 cc of oil in the engine. Shell Thuet seemed to feel strongly that this amount was way too much oil and it would just get blown out the breather. He and others ran quite a bit less. By the 75B, Yamaha started agreeing and reduced the amount called for to 2500 cc dry and 2000 cc for periodical service changes. They altered the 'Dipsticks' thereafter accordingly also to adjust level indicators as well.

Further looks lead one to believe that leaning the bike to the left on the sidestand right after shutdown would leave quite a bit
of oil in the top end that would not have drained back down to the crankcase. If then started before it drained down the center tower
a goodly amount could get blown out the breather. Bit of speculation there but; a little food for possibility thought.

That tech bulletin sheet could be helpful for re-marking your dipstick also. Might be helpful to compare your 73' dipstick to
the 75' plus ones. Best, Blue

 

[JasperLP]

I always thought they changed the oil capacity from 3000cc to 2500cc in '72, when they added the electric starter. The starter took up crankcase volume!

 

[Tomterrific]

I thought the dipstick change came after '75 but really don't know. Does your breather have rubber tubes stuck in the outlet nipples, seemingly as an afterthough? The later XS has this from the factory to calm down the ingress and egress of air, don't know about the '73. I almost pulled mine out of my '77 so I wouldn't put it past a PO pulling those inch long rubber hose stubbs out of a breather.

Does the oil level grow? The floats or the needle and seat may be leaking. This dribbles gas into the cylinder and past the rings to raise the level, dilute and thin the oil with the water thin gas. The engine might smoke on start-up with this symptom.

A couple of check valves in the breather line may help if everything else checks out okay. While the vacuum won't hold in the oil at teh breather like it does gaskets and seals, the thinner air in teh crankcase will not blow the oil mist around in a hurricane quite so bad.

Tom Graham

 

[cmattina1]

my only 2 cents are... i had oil coming out my tubes before the engine crapped out... and it was coming out of the tubs when it was low on oil, so, i know for sure, that oil CAN come out regardless of how little or much oil is in there.

 

[OakBehringer]

I always thought they changed the oil capacity from 3000cc to 2500cc in '72, when they added the electric starter. The starter took up crankcase volume!

I think you're right, my '73 is marked 2500cc on the crankcase.

Does your breather have rubber tubes stuck in the outlet nipples, seemingly as an afterthough? The later XS has this from the factory to calm down the ingress and egress of air, don't know about the '73. I almost pulled mine out of my '77 so I wouldn't put it past a PO pulling those inch long rubber hose stubbs out of a breather.

Nope, although I'm not really sure what you mean. I have the stock, large dia tubes that go on the breather nipples, and run down the backbone, behind the motor. There's nothing in the nipples.

Does the oil level grow?

Nope, it diminishes.

A couple of check valves in the breather line may help if everything else checks out okay. While the vacuum won't hold in the oil at teh breather like it does gaskets and seals, the thinner air in teh crankcase will not blow the oil mist around in a hurricane quite so bad.

Interesting. I was thinking that they would have no effect, as they are one-way, still allowing the oil to come out, but your lower-pressure evaluation is not something I considered. I'll give it a try.

Sorry for my slow responses these days. I've been doing major work cleaning and re-arranging/re-organizing my shop. I value everyone taking the time to respond. Thanks again!

Adam

 

[ProSimex]

Its just doing what any good bike should do, its marking its territory. I dont trust a bike that doesnt leak oil, seems unnatural.