Oil breather pipe

uncle meat

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Went on my first lengthy ride today (70 miles) after having the top end rebuilt. Noticed that the Y shaped oil breather pipe had been leaking oil on the left side. There are no hoses attached, fyi. I also was careful to keep the speed down, for break-in purposes.
Is this supposed to happen? Is there a reason this is happening?

UM
 
Yes, I'd say it's pretty normal, and could be worse than usual if you have the oil level in the engine above half full. Yamaha discovered they had over-done the breather outlets. They were getting complaints from owners about excess oil coming out them. They took various steps over the years to alleviate the problem. The big one was reducing the oil amount used in the crankcase. The problem got better but I don't think it ever completely went away. Their first breather assembly "fix" was to plug one outlet completely and just use the other one. This was in the early to mid '70s before E.P.A. mandates. The one hose was run down into the left side cover, poised above the chain. If any oil did come out, it was like having an automatic chain oiler, lol.

74-75Breather.jpg


When E.P.A. mandates came into effect, they had to "recycle" the oil vapor back through the motor. They went back to the two outlets, directing one hose to the intake of each carb so they could divide the oil mist equally between the cylinders. Since they knew the outlets were too big, they sleeved them down with rubber plugs that had about 1/8" holes in them .....

BreatherPlugs.jpg


Eventually, they redesigned the housing with only one outlet and the reduced hole size built in .....

LateBreather.jpg


I'm assuming you're running yours with the outlets wide open. That will most likely prove to be too much and be kinda messy.
 
Thanks for the response 5T, you are right, mine are wide open. I think I shall invest in some breather hoses to keep the oil off the top of my carbs, which ends up on the chain, rim and tire...what a mess. And yes, my oil level is too high. I plan on changing the oil next weekend and will make sure it's at the proper level. I'll also manufacture some sort of sleeve as well.
I hope the engineer took credit for his auto chain lube hose, that cracked me up!

UM
 
You can fit the later one outlet housing, it will swap right on. You would need it complete with it's internal baffle plate as it differs from your earlier one. The breather hose MikesXS sells is very nice, same size as the original (thin wall). They also have the protection spring that keeps it from kinking and/or collapsing. One spring is all you need, it can be cut in half. Mike's sells the hose in short pieces or a long 3' length. I get the long one because I replace these on practically every 650 I work on. The originals are hard as a rock now, lol.
 
With today's o-ring chains do you want to put it on the chain?
Hi WER,
too effin' right you do! More so on a sealed chain than on an ordinary one.
The O-rings (or X-rings or whatever the letter of the month is-rings) keep the original chain lube inside the rollers
so that the chain itself stays oiled over time.
Which means the lube can't get out to keep the chain roller/sprocket interface oiled and that interface needs oiling too.
Which is why you should regularly use chain oil or have the engine breather hose pant engine oil vapour onto the chain or
install a ScottOiler or other automatic chain oiling device to drip propriatory chain oil (Mr. Cheapskate uses chainsaw bar oil)
onto the chain.
 
knuckles that was a question not a statement.
Directed not just to you but the community at large.
I'll take it you are in the oil the shite outta them camp.
But if you want I can stir the shit pot with the best of them.
Because of my lifestyle I've gotten a boatload of experience with sprockets and chains.
IMG_20150608_141808_907.jpg


Others (5twins) that use the older non-sealed chain that is a whole different game.
We can read (at least I have) different opinions on this.
I'm waiting for the person that can say I applied used oil to my chain and it lasted half a million miles (ok tongue in cheek exaggeration there)
or the person that says I applied used motor oil and deteriorated my o rings prematurely.
I have never heard personal experience but talking heads usually promoting their product.

Now to Fred.
I guess I should have clarified "do you want to put used oil vapor on an o-ring chain".
I didn't ask about new oil of any variety.
And if I wanted a automatic chain oiler Vermeer has some nice units on their balers I could rob in any ag scrap yard a lot cheaper than
the price of a scottoiler. That is your Mr. Cheapo tip of the day.
Please take note of the picture. Some are lubed quite often and you better cause they are NOT sealed units.
And I have been the route of cheap but for prolonged chain life a new oil (90W gear oil) is best for me.
Whatever the chain is driving.

Note to Travis. I like the new software notice of additional posts. Gives me a chance to review before I hit post reply.
 
- - - Now to Fred.
I guess I should have clarified "do you want to put used oil vapor on an o-ring chain".
I didn't ask about new oil of any variety.
And if I wanted a automatic chain oiler Vermeer has some nice units on their balers I could rob in any ag scrap yard a lot cheaper than
the price of a scottoiler. That is your Mr. Cheapo tip of the day.
Please take note of the picture. Some are lubed quite often and you better cause they are NOT sealed units.
And I have been the route of cheap but for prolonged chain life a new oil (90W gear oil) is best for me.
Whatever the chain is driving. - - -.

Hi WER,
"used oil?" Whyever not? If it's still new enough to keep my engine's innards lubed it's gonna be OK on my drive chain too.
Even if it is 20W50 engine oil instead of 90Weight gear oil it is getting there as a constant vapour flow instead of the flood/fling off/repeat next week
cycle with 90 Weight gear oil.
And yes, a salvaged Vermeer may well work as well as a new propriatory motorcycle-specific chain oiler but first you gotta have access to an ag scrapyard,
which us city boys usually don't.
As for oil cost, Clingtex or other chainsaw bar oil costs about the same as gear oil and it don't fling off as quick.
 
Chain oil? You know its just 30wt right? I buy wolfshead 30wt, wich is very cheap , for my chain saws. Turns to shit in a engine though
 
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