/04 RMZ 250 Oil Comeing Out Breather Hose

Hello again, I took my new bike out from the basement for its first ride around the yard.

After getting it running, oil started running out in a constant stream from the breather hose.. ( I think thats what that hose comes from..? ) I shut it off right away, but about half a cup of oil ran out. I did all the pe-start checks that the manual has. The oil level was not over full according to the sight glass......Has anyone had the same experiance....? This can`t be normal...?

Any suggestions......?

Thanks for your help.......!


I've had this happen before. I remeber seeing a post on hear that one of the reason's this problem could occour could just be revving up the motor and then just shutting it off, this leaves oil up in the head, when in fact you should let the motor idle for 10 seconds. The other explanation for this problem was that the motor was to full of oil. I have only had this happen twice, and it just seemed to be hit or miss, I let my bike idel for about 10 seconds and have had no problems.

you cannot go by the sight glass. the oil sits in the sump , and gives a false reading. measure out 1.3 liters and go by that religously .

I have not had oil puke out on me yet, but i have read it here that it happens.

do a search on prevous posts.

Hello, Thanks for your information. Can you explain why the level in the sight glass would give a false reading.....?

It has only been run a couple of times for only a minute or two, would the small amount of oil that came out make a differnce in the oil level that come from the factory...? Should I drain it and refill...? What do you recommend for oil..?

Thanks, Frank, W`Lake, BC

you cannot go by the sight glass. the oil sits in the sump , and gives a false reading.

that's why

Isn't that a bit misleading? You have to check the oil just like the WR and many others by running the bike for a bit, then shut it off, wait a minute, then check oil. The last part of the check is looking thru the window. Now if you just look thru the window after the bike sat all week in the garage like so many people are doing, then it will look low. People assume you can just look thru the window at any time and not do the procedure. If they made it a dip stick, it would be the same procedure, although I bet people would do it right. It is different than the klx300 where you just look thru it before you start it. If you just add a set amount of oil, over time you may accumulate too much oil. It's not a bad method, and is a good second check to the sight glass, thats how I would use it. Can you be sure you drained it completely before you added the same amount of oil? On average I bet it works out ok, but the sight glass method is still good to tell the actual level of oil.

If you change your oil often you should not worry about the sight glass level, just put in the specified amount.

Same happened here to me but except it was antifreeze coming out of the anti freeze tube what kind of bike does this brand spanking new it was cold when it was leaking and yeah would the cold be the reason? but truthfully that ticks me off u know BRAND NEW!!! Any ideas why this have happined??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? :cry:

Maybe your bike started to over heat, or the collant froze up, or you had to much collant.

actually if the bike sat all week, and the oil drained back from the filter and the head the oil level would be high in the sight glass, not low, if you change your filter every other ride or 3rd ride, one liter of oil is sufficient as long as you are not draining the small filter bolt{which there is really no need to} The bolt is directly under the screens, and there is very little oil in the cavity, not to mention if your changing the oil that often anyway, that small of an amount will blend, i've owned all 3 of my bikes since they came on the market and have never removed the small drain plug bolt.

Seen this happen numerous times. Each and every time the bike had too much oil and it was leaning over on the triangle either for quite some time or while it was running. There is actually a service bulletin regarding the special method that you need to follow for checking and refilling the oil on the KX250F.

It was my 05 that had this same problem. EVERYTIME i filled it with exactly 1.3 (sometimes 1.2 as experiment) it'd spill oil. The last time I changed my oil, I tipped the bike as far to the right as possible without letting go and started her up -- didn't drip. Although I haven't run it since then...

Is the hose from the breather tube routed up and around the intake like it should be

if the hose is not once a round the intake the oil will come out of the engine breather

check the oil with bike level /straight and cool it should be at the top 3/4 of the sight glass :)

Sounds like the oil is over filled. I had it happen a few times after oil changes. If you go off the sight glass-use the bottom mark as full. Oil level is very critical on these bikes or it will blow out of the breather. Make sure your breather is not plugged. I take it off at the engine every few rides and blow it out with compressed air. I know a guy locally that ovr filled his KXF and had a clogged breather and it blew the sight glass out of the cover.

couple things,

If bike is brand new or still before first service, chances are the person at the dealership who prepped or serviced the bike was a retard. One of the first bulletins issued by suzuki was due to people who were in charge of pdi'ing the bike were adding oil till it read in the sight glass.

What weight oil and what is the temperature that the bike is being ran in. 20 degree weather and 10w40 oil , you can almost count on some oil being pushed out the breather till the motor warms up and the viscosity of the oil reduces

Last check the breather hose routing if it is mis-routed or pinched this could cause isssues also.

I had the issue of oil as well. It only happened once after I re installed the head. I like to pour a lot of oil in the top of the head around the cam buckets, cam lobes etc. I also tipped the bike over to the right when I filled the coolant. It only lasted a short time and stopped. I also like to pull the engine breather hose back through a bit so it's not sitting tightly over the carby intake.

I bought my RMZ in December of 2004, brand new. I had the same problem with oil pumping out the drain hose significantly like you described. Pay attention to these symptoms and make sure you do not see blue smoke coming out your exhaust. This would be an indication your bike is burning oil and the rings are not properly seating. If the rings do not seat properly this pressurizes the crank case and leads to oil pumping out the vent hose significantly as you described. My bike drained oil before I ever got to ride it directly from the dealership who refused to take back the bike, then blue smoke began coming out the exhaust after two rides. I have taken my bike in 6 times for these problems, I am on my third documented time. My bike is back in the shop for a second engine rebuild. Suzuki has been great backing their product by authorizing engine rebuilds. Evidently some cylinders did not get proper coating when manufactured is what I am being told from my dealership, after they spoke directly to Suzuki. I enjoy the power and agility of the bike but I am concerned about reliability. Good Luck!

Thanks for the great information.


If the rings do not seat properly it cannot build excessive pressure to be pushing anything out of the crankcase..... I don't have my manual or fiche in front of me but isn't there a reed valve in the case halves, I suspect this probably cracked or if stuck partially open due to debris and thus could be why there is excessive drainage thru the vent tube. Cylinders not getting plated, doubt it, in for 2nd rebuild for same problem, find a different shop...

Why does the oil breather have to go up and around the carb? It really gets in the way of things (like the easy adjust fuel screw which isn't so easy with that stupid tube in the way)....

Yes as you can guess I've already rerouted it straight down so tell me how I screwed up.

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