99 400ex crankcase overfull

[jsl1213]

just got this quad. recent rebuild. oil isn't returning to tank, staying in crankcase.checked filter,took off return line blew air got some gunk out,reassembled filled with oil same thing happened.had an oil leak @ valve cover, thought that it was losing that much,fixed that. at first they just kept adding oil because it wasn't on dipstick, blew oil out of breather and exhaust. nobody ever heard of this. can someone help with this?

[togup]

By what information you've shared I would pull your oil pump , disassemble it and check the impeller as specified by the honda manual. Sounds like its not picking up the oil , also there is a filter at the bottom of the case (pump suction)that could be clogged.

[jsl1213]

when we had return line off,we cranked it over and it put oil out of case, but maybe not enough??

[rubbersdown]

kind of sounds like one of your return oil passages it blocked up and not letting the return like pressurize to refill the tank.

[jsl1213]

you mean oil passage in block?

[rubbersdown]

yah, oil pumps mechanical so as long as its not super warn or jacked up its going to pump. If you can find out what the return oil pressure is supposed to be id check it and see what yours is at.

[togup]

If you think its a blocked oil line simply put air to one of the lines if it pressurizes its blocked ,of course that means youll have oil spraying everywhere. you said you already blew out the return line I still think its the oil pump filter screen.

[jsl1213]

ok guys thanks for the info. we'll try and see what happens. any other input greatly appreciated !!

[jsl1213]

ok,took off rt. cover, screen wasn't dirty enough to block oil.
do you have to remove clutch to get oil pump out?
do you have to remove left cover to check oil passages?

[99RED4X4]

I just my right case off the other day, and in my opinion I'd say you do not have to remove the clutch to get the oil pump off.

[dalejiw25]

The clutch assembly has to be removed.

[99RED4X4]

Sorry for giving incorrect advise. I guess I was just thinking about the drive gear. I know it pops right off.

In any case, If your working on a problem like this I'd refer to this manual

http://www.maxmekker.com/atv/Manuals/Honda/Honda%20400ex.pdf

I use this and the clymer manual

[jsl1213]

what about lft side to check passages?

[jsl1213]

we have a clymers.

[dalejiw25]

No oil passages behind left side cover. The oil passage is behind the oil pump. The pump pushes oil through the passage.

[dalejiw25]

Have you checked the screen in your oil tank ???? Is your oil filter installed correctly ????

[99RED4X4]

How about the screen below the clutch plates?

[jsl1213]

didn't check screen,but isn't that on the supply side? check the screen in
in case it was ok.

[99RED4X4]

The screen on the oil tank is on the bottom line, not sure if that supply or feed. It should talk about it in the clymer manual.

[jsl1213]

hate to sound tupid,but how much play should be in timing chain,doesn't
really say in man.

[jsl1213]

now i'm really confused. oil pump seems ok and all passages are clear.
NOW WHAT ??

[dalejiw25]

Doesn't matter whether it's supply or return. If you want the problem resolved answer the questions asked of you. Did you check the screen in your oil tank and is your oil filter installed correctly ???? The Cam chain has nothing to do with oil flow. Stay on topic. One problem at a time. 99red, He said "ok,took off rt. cover, screen wasn't dirty enough to block oil." That's the screen below the clutch.

[jsl1213]

sorry! as i previously said oil filter was ok.tank screen is clean.

[togup]

check the oil lines coming into the motor and make sure they are not crossed up

[jsl1213]

guys,thanks for all the info. think we may have found the problem!
we rechecked the oil lines and found when we blew air through the
return line it had more resistance going the flow direction than it
did the opposite way. think the line came apart on inside. getting new line & try it again.