puking oil into air box ???????

[Hansman]

Hey guys,I just bought a used 400ex,and have now discovered that after the engine has run a few minutes,it pushes oil out the crank vent tube,(which I have now discovered on this bile has been relocated up the frame and is just a hose running to the nipple on the crank case) I also see now the place in the air box where the original hose is supposedto be attached was capped off.
I`m an auto technician,so I understand 4 stroke motors,but dont have much experience,with these particular engines.
It starts right up,makes zero smoke,has good power,which all tellsme that the rings,compression etc should be good.
However this engine has been apart recently for a ft sprocket,bearing/case repair,and I just have to wonder if that could be where this problem started ?
hopefully some of you guys have seen or at least hweard of this before ???

[Pipeless416]

everytime ive heard of this happening its just from being overfilled. could too much oil have been added after all this work was done?

[GPracer2500]

And pay close attention to the oil fill/check procedure. It's a dry sump engine so there's a particular method for getting an accurate oil reading. Overfilling is common when done wrong.

[440challenger]

rings shot from dirt sucked into intake causing blow by making more crankcase pressure?

[hornetgod13]

Do a compression check. It should be between 100 and 128psi warm. If the numbers are good than as the others mentioned, the previous owner over serviced it. Both the crankcase and oil tank need drained when changing the oil. Just a tick under 2 quarts of oil is what it takes. If he did'nt drain the crankcase than it will push the oil out the breather line.

[powermadd400ex]

my 400ex has had its oil changed twice.
the dealer did the first time for the after break in period
and i did it recently. but i only drained the oil tank. nothings wrong right?

[billyboy93]

Originally posted by powermadd400ex
my 400ex has had its oil changed twice.
the dealer did the first time for the after break in period
and i did it recently. but i only drained the oil tank. nothings wrong right?



you need to drain the crankcase with the oil tank and change the oil filter

Originally posted by my88r
i would try changing the oil. make sure you change it at both drain holes. like pipe said its probably to much oil.

Both holes?? Is that the dry sump and the engine block?

[hornetgod13]

Originally posted by powermadd400ex
my 400ex has had its oil changed twice.
the dealer did the first time for the after break in period
and i did it recently. but i only drained the oil tank. nothings wrong right?

How much oil did you put in? If you put 2 quarts of oil in than it's over serviced. If it has too mucj oil the excess get's pushed out the crankcase breather.

[krt400ex]

Originally posted by Ikilla2
Both holes?? Is that the dry sump and the engine block?

on the left side of the engine kinda towards the rear and a little in front of the sprocket there is a small drain plug. i think it is a like a 12mm or something. that is the other drain plug.

you need to drain that and the tank. when i do it...i usually tip the machine a little bit to really empty it out, though this is not really needed. the bike will take just about 2 qts of oil

[powermadd400ex]

Originally posted by hornetgod13
How much oil did you put in? If you put 2 quarts of oil in than it's over serviced. If it has too mucj oil the excess get's pushed out the crankcase breather.

a lil under 1.8 quarts.

If you change your oil filter too you might need to put a full 2 quarts in.

[kraemer]

i think you are refering to the airbox drain pipe. it could be plugged off, your CCV should go to a small clear reservior and then should be fine. straight to the rubber intake hose, before the carb...

[Hansman]

OK ,guys ,thanks for the help....so if the oil level on the dipstick shows between low and hi,(in the crosshatched area)does that mean it could still be overfilled then?????????????
:eek2:

[GPracer2500]

Originally posted by Hansman
OK ,guys ,thanks for the help....so if the oil level on the dipstick shows between low and hi,(in the crosshatched area)does that mean it could still be overfilled then?????????????
:eek2:

If the engine is cold, yes.



To check the oil level:

--Let engine idle for 5 minutes. Don't rev, don't ride--IDLE.
--Kill engine and wait 1 minute.
--Unscrew dipstick, pull, wipe, and replace without screwing it in.
--Read oil level.

When the engine sits for a while, the oil slowly drains out of the oil tank and into the crankcase. If you check/top-off the oil at that time the dipstick will read as though it's low on oil. That's when folks tend to overfill. When the engine idles up to full operating temperature the oil pump normalizes the oil level in the crankcase. The excess gets recycled into the oil tank and maintains a certain level of oil in there.

There is also an oil-check bolt on the crankcase. It's down by the oil lines below the oil filter. It's not really for checking the total oil level. It's for confirming the oil pump is maintaining the correct level in the case at idle speed. When warm and idling, that bolt can be removed and the oil level in the crankcase should be even with the bolt hole. You shouldn't really need to check anything to do with the crankcase oil check bolt unless you suspect an oil pump problem. I mention it only FYI.

[NacsMXer]

Originally posted by powermadd400ex
a lil under 1.8 quarts.

1.95 quarts is the spec in the manual following a complete oil/filter change.

Originally posted by GPracer2500
When the engine sits for a while, the oil slowly drains out of the oil tank and into the crankcase.

yeah I did an oil change rode once checked the oil it was pretty high and it was where it shpuld be when its hot on the upper section of the crosshatches of the dipstick. I hadnt gone riding in 2 weeks or so I went to go riding and i always do a check before leaving. I look at the dipstick my reaction "WTF theres no oil!" I start checking for a loose drain bolt and a puddle of oil, my valve cover caps were leaking and so was my oil filter cover but it was so minimal and the motor was sitting where could it have gone. I started it let it idle for 5 seconds. Checked the dipstick still nothing! now i'm getting worried. I start it let it idle for 15 seconds or so finally a bit of oil on the dip stick. I let it go for 2 minutes check it and its higher ut still low, let it go 3 more for the full idle oil check procedure and aha oil at last it was fine lol

[Hansman]

OK guys,here goes...thanks for the responses so far,especially for GPRacer2500,
I started it cold,let it IDLE for 5 minutes ,shut it off for a minute or two ,then checked the level on the stick...there was barely a drop on the bottom on the stick,and it had blown alot of oil out of the makeshift crank vent hose.
However there doesnt seem to be hardly any pressure coming out of the vent hose,its just gurgling out the oil,remember this engine was at least partially down recently for a drive sprocket/housing replacement and I cant help but believe that this problem probably has been caused by that.
let me know what you think ??

[justin1022]

Originally posted by hornetgod13
How much oil did you put in? If you put 2 quarts of oil in than it's over serviced. If it has too mucj oil the excess get's pushed out the crankcase breather.

if you over fill it wont it smoke a bit too?

[Hansman]

I would expect that it would smoke some,it it were over filled/It seems like my problem could have something to do with an internal gasket or seal issue...I just dont want to tear it down until I`m a little more sure of what to look for...;) ;)
hopefully someone more knowledgable will reply.