How much oil leak out of breather hose is ok?


23 replies to this topic
  • CO_Rider

Posted February 10, 2008 - 07:48 AM

#1

I know some oil leak out of the valve cover breather hose is normal, but exactly how much? It seems like my bike always leaks oil out of the hose and leaves a little puddle (a wild guess would be 5 drops or so). I know it does it when I am riding also because you can see traces of oil sprayed around the frame under the front sprocket. Does this sound normal? I am not losing enough oil to have to top it off between my oil changes which is every 2 rides. If this is not normal what could be the problem besides over filling the oil? I know I am not over filling because everything is good when I check the stick. I would say the bike has about 15 hours on it. Any ideas or thoughts?

  • Ga426owner

Posted February 10, 2008 - 08:01 AM

#2

I know some oil leak out of the valve cover breather hose is normal, but exactly how much? It seems like my bike always leaks oil out of the hose and leaves a little puddle (a wild guess would be 5 drops or so). I know it does it when I am riding also because you can see traces of oil sprayed around the frame under the front sprocket. Does this sound normal? I am not losing enough oil to have to top it off between my oil changes which is every 2 rides. If this is not normal what could be the problem besides over filling the oil? I know I am not over filling because everything is good when I check the stick. I would say the bike has about 15 hours on it. Any ideas or thoughts?



yes it is getting overfilled....when you add new oil, let the bike run for a min. then check oil level 30-40sec later. This is when height is at it's fullest. Sign of overfill is when oil creeps out of the dipstick hole. There has been no issues due to several drops coming out. Some riders run the oil height higher than others. Just make sure it is not underfilled or way overfilled and you will be ok

  • CO_Rider

Posted February 10, 2008 - 08:31 AM

#3

Thanks for the tip :applause: I dont have any oil leaking out of the dipstick hole, just the valve cover breather hose. I guess I dont know for sure if I am over filling but like I said everthing checks out with the stick. I will wait the 30-40 seconds and check. My bike calls for 1.06 quarts but I have been putting in just 1 quart (instead of putting in .06 more of 1) and that brings it right up to a little past the lower line so I really wouldn't have thought I was over filling. :)

  • 426boy

Posted February 10, 2008 - 02:43 PM

#4

i think that is prety normal, but it is more than mine. my 426 only leaks out like oil residue dont think i have ever seen drips, maby one or two at the most

  • CO_Rider

Posted February 10, 2008 - 11:43 PM

#5

Ok thanks fellas. Yeah I think mine is the oil residue also that just collects at the bottom of the tube which turns into a drip. I dont think it is just straight oil leaking out, but what got me was it was happening all the time and like I said it was spraying a little when I ride. Just didnt know how much was actually ok and how much would make it a problem. I will just make sure to really be double checking my oil level. With only 15 or so hours on the bike I was just hoping it wasn't rings like maybe they didn't seat right when I broke it in.

  • stroker101

Posted February 11, 2008 - 05:28 AM

#6

i beleive that excessive "blow by" can contribute to this condition also.

  • CO_Rider

Posted February 11, 2008 - 09:34 AM

#7

i beleive that excessive "blow by" can contribute to this condition also.


This is kind of what I am worried about. I have been searching around on here and have found that this could be a cause of it. Thats why I am trying to get an idea of how much oil coming out of the tube would be considered normal and how much would be a concern. :applause: I really dont want to have to tear into my motor yet with only around 15 hrs on it especially since I have never done it before. I guess if I have to already than I have to. Is there a way to tell if the rings didnt seat right or there is excessive "blow by" without taking the motor apart? The bike runs real strong otherwise and fires up pretty easy :) Sorry for all the questions but I am just trying to figure this out so I can ride without any concern.

  • stroker101

Posted February 11, 2008 - 01:37 PM

#8

with only 15 or so hrs on the bike, i doubt that blow by would be the main reason for the oil dripping. as mentioned earlier, you may have put in too much oil and as a result...the drips.

what yr and model is your bike? was it recently overhualed?

  • CO_Rider

Posted February 11, 2008 - 11:52 PM

#9

with only 15 or so hrs on the bike, i doubt that blow by would be the main reason for the oil dripping. as mentioned earlier, you may have put in too much oil and as a result...the drips.

what yr and model is your bike? was it recently overhualed?


Its an 07 YZ450. The 15 hrs have been since new, no overhaul. Honestly I am now thinking it is from too much oil also and after reading on here and talking with other people it seems like the amount of oil isnt that much. It seems that if there is a problem I would be losing quite a bit more then just the few drops. I just did another oil change and really paid attention and waited the 30-40 seconds to check the stick and everything checked out. Will just have to wait and see after the next time I get to ride. Thanks for the help guys I really appreciate it :applause:

  • jeeper33

Posted February 12, 2008 - 02:48 PM

#10

in my experience, a few drops are ok. the reason for that hose is to not allow too much negative/positive pressure build up where it isn't supposed to be. pretty much every yamaha bike ive been introduced to(bigger bikes that is, and mx bikes particularly) has had some oil drippage, or accumulation on the opening of the breather hose. This is OK. If you'll notice, all the pro supermoto bikes have to have accumulation containers attached to any overfill/overheat/breather hoses to avoid spilling anything on the track..many of the 450's out there end up having oil in the container after the race.

if it really bothers you, you can invest in a catch-can like this one: Catch-Can on ebay. or make your own out of a small bottle and some duct tape(works just as well for keeping the fluids off the track.

As long as you dont park your bike, walk away, and come back to a puddle(more than 1-3 drops) you're within the tolerable limits. just make sure you're putting the right amount in. the older YZ's could take extra oil without any build up in pressure because of the way the oil was stored in the frame behind the steering bearings..not sure about the 07. Let me know if refilling it and watching it turns out to be leak free

~Jeep

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  • YZERIK

Posted February 13, 2008 - 07:46 AM

#11

time for a rebuild

  • CO_Rider

Posted February 13, 2008 - 08:49 AM

#12

in my experience, a few drops are ok. the reason for that hose is to not allow too much negative/positive pressure build up where it isn't supposed to be. pretty much every yamaha bike ive been introduced to(bigger bikes that is, and mx bikes particularly) has had some oil drippage, or accumulation on the opening of the breather hose. This is OK. If you'll notice, all the pro supermoto bikes have to have accumulation containers attached to any overfill/overheat/breather hoses to avoid spilling anything on the track..many of the 450's out there end up having oil in the container after the race.

if it really bothers you, you can invest in a catch-can like this one: Catch-Can on ebay. or make your own out of a small bottle and some duct tape(works just as well for keeping the fluids off the track.

As long as you dont park your bike, walk away, and come back to a puddle(more than 1-3 drops) you're within the tolerable limits. just make sure you're putting the right amount in. the older YZ's could take extra oil without any build up in pressure because of the way the oil was stored in the frame behind the steering bearings..not sure about the 07. Let me know if refilling it and watching it turns out to be leak free

~Jeep


Thanks Jeeper :applause: It doesnt bother me but I was just curious as to how much was ok. I will check it out this weekend and see how much is leaking out after this last oil change.

  • CO_Rider

Posted February 13, 2008 - 08:52 AM

#13

time for a rebuild


Thanks for your input YZERIK. So you think the rings didnt seat right and I am getting to much blow by? Or something else?

  • Ga426owner

Posted February 13, 2008 - 09:00 AM

#14

time for a rebuild


ok explain why you think it needs a rebuild at 15hrs......please

  • grayracer513

Posted February 13, 2008 - 09:48 AM

#15

time for a rebuild

That's ridiculous.

There isn't anything particularly abnormal about that amount of oil blown out of the the breather. My older '06 that my son rides blows stuff down the frame rail more than mine does because the tube keeps slipping in its clamps, and because he rides the crap out of the thing. That bike is nowhere near needing a rebuild, either.

There are two ways to verify that you are not overfilling. Probably the most reliable way is to deliberately UNDER fill by 100cc or so, then work up to the right amount in 50cc increments. The other way is to fill, run the engine, shut down, and after 1 minute, pull the overfill check bolt (behind the shifter, page 3-14 in your manual). This is a level plug that works because the system is designed so that there is so little "extra" room in the tank that almost any overfill results in the excess being forced back to the sump through the pressure balance line on the right side. That increases the sump level to an abnormally high point, and the check bolt is positioned so that it will drain down to the correct height. Let it drain for no more than 2 minutes after the flow slows significantly.

The only way to know with any certainty that the compression rings are not sealing as they should is to run a leakdown test on it.

  • 917 rider

Posted February 13, 2008 - 10:24 AM

#16

be glad its only a few drops,i had a crf 450 and the tube splits,one goes down the other to the breather.you coud ride for ten minutes and the hole air box and air breather would be covered in oil and the swingarm,thats when you need a rebuild:cry: my 08 yz takes a quart and a peice. i always start with one quart let it run for a minute or two then check and add a little at a time,the only time ive notice any oil is when i ride hard and there will be a couple of drops on my stand you will be fine:ride:

  • CO_Rider

Posted February 13, 2008 - 10:56 AM

#17

That's ridiculous.

There isn't anything particularly abnormal about that amount of oil blown out of the the breather. My older '06 that my son rides blows stuff down the frame rail more than mine does because the tube keeps slipping in its clamps, and because he rides the crap out of the thing. That bike is nowhere near needing a rebuild, either.

There are two ways to verify that you are not overfilling. Probably the most reliable way is to deliberately UNDER fill by 100cc or so, then work up to the right amount in 50cc increments. The other way is to fill, run the engine, shut down, and after 1 minute, pull the overfill check bolt (behind the shifter, page 3-14 in your manual). This is a level plug that works because the system is designed so that there is so little "extra" room in the tank that almost any overfill results in the excess being forced back to the sump through the pressure balance line on the right side. That increases the sump level to an abnormally high point, and the check bolt is positioned so that it will drain down to the correct height. Let it drain for no more than 2 minutes after the flow slows significantly.

The only way to know with any certainty that the compression rings are not sealing as they should is to run a leakdown test on it.


Thanks Gray. I tried using that check bolt once before but honestly didn't know how accurate it was because it seemed like a lot of oil would come out even though I only put in 1 quart instead of the 1.06 quart it called for. It makes sense on how it works though :applause: Im glad you mentioned that on one of your bikes you are seeing some spray down the side of the frame rail because that is what had me concered. That is what I have seen lately but now I am riding desert so it is a lot of just wide open stuff so like your son just really riding the snot out of it. I never noticed it really trail riding but I also wasnt getting on it as much for as long so I bet that is contributing to it. I will try your method of underfilling and then going from there next oil change.

  • CO_Rider

Posted February 13, 2008 - 11:04 AM

#18

be glad its only a few drops,i had a crf 450 and the tube splits,one goes down the other to the breather.you coud ride for ten minutes and the hole air box and air breather would be covered in oil and the swingarm,thats when you need a rebuild:cry: my 08 yz takes a quart and a peice. i always start with one quart let it run for a minute or two then check and add a little at a time,the only time ive notice any oil is when i ride hard and there will be a couple of drops on my stand you will be fine:ride:


Thats what I figured about the oil leaking out. I think it would be a lot more if there was a problem after talking with some people and reading some other posts on here. You just confirmed it also :applause: even though you found out the bad way :) Yeah my 07 calls for a touch over 1 quart (1.06) but like I said i have just been puttin in 1 quart and that brings up the level to just a little above the lower line on the stick so in the lower part of the recommended level.

Thanks again everybody for all you help :cry: You guys rock!

  • grayracer513

Posted February 13, 2008 - 11:36 AM

#19

I tried using that check bolt once before but honestly didn't know how accurate it was because it seemed like a lot of oil would come out even though I only put in 1 quart instead of the 1.06 quart it called for. It makes sense on how it works though :applause:

I'm not totally convinced of how well the OF plug thing works, either, to be frank, but one thing that is certain: You MUST run the bike long enough to "normalize" the oil levels in the tank and sump BEFORE you remove the bolt. If you do it in reverse of that, you'll simply drain off most of what you just poured in.

Yamaha complicates the whole concept of dry sump oiling in people's minds by having the oil fill go to the sump, where the oil doesn't really belong. Only by running the engine do things get distributed to their true operating levels. As if dry sump wasn't hard enough to explain already....:)

  • CO_Rider

Posted February 13, 2008 - 12:00 PM

#20

I'm not totally convinced of how well the OF plug thing works, either, to be frank, but one thing that is certain: You MUST run the bike long enough to "normalize" the oil levels in the tank and sump BEFORE you remove the bolt. If you do it in reverse of that, you'll simply drain off most of what you just poured in.

Yamaha complicates the whole concept of dry sump oiling in people's minds by having the oil fill go to the sump, where the oil doesn't really belong. Only by running the engine do things get distributed to their true operating levels. As if dry sump wasn't hard enough to explain already....:applause:


Exactly what happened. I must have not done it right because it drained out a lot and I had to top it off. Since then I have not tried it again. If I overfill sometime I will try it again after running it for a while and see what happens. Yeah I dont really understand the whole dry sump thing except something about you dont have to have a lot of oil in a resevior under the motor because it takes it from where ever to the pump and then goes from there..:) (haha if that even makes any sense)





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