oil blowing into air case HELP!

Thanks for the response on my last post everyone. I cleaned the crap out of my carbs and my bike starts now and runs nicely except for the fact that oil is blowing out of what I think is the gearbox (left side of the bike, next to the shifter) into my air tank and then spewing out onto the ground. There is a tube coming out of this thing going directly into the air box. Note- this bike was stored for 13 years and then sold to me AS-IS. I took a risk and as of tonights hard work, seems to be paying off except for this problem. I have an 83 XJ750 Maxim... THANKS!!! This site is great!

 

That should be your crank case breather and if the leak is coming out of the airbox, you got problems. Is your oil level correct? An over fill condition will cause this problem as will worn rings. Have you done a compression check of the cylinders? Get some info on your machine and let us know what you find.

 

I would also check for fuel in your crankcase. This can cause a high oil level and allow it to be blown into the air box. I would also do a compression check on the cylinders if you donot find a high oil level.

 

It's probably not oil but fuel leaking out the carbs and running out unless the crankcase is overfilled. A gas leak can look a lot like oil.

 

ok, for the past week the carbs were leaking gas very badly and it seemed as if it were being dumped into the air box and then coming out. I tore out the carbs, cleaned them heavily and the gas leak stopped. Then after I got it running pretty consistantly, this was happening last night. Is it possible that gas from the last week got down into that hose and into the crank case and now it is starting to spit it out on purpose?

Also, when my bike is on it's kick stand, I cant see any oil in the clear window deal. but as soon as I barely lift it off, before it is even straight up the oil completely covers the window. Could be an over full oil?

 

That's exactly what I think it is and exactly why I advised you to check the crankcase for fuel. You can do this by removing the filler cap and smelling. The carbs can overflow not into the breather tube but into the intakes and then into whichever cylinder has an open valve. If you find fuel, drain the oil and replace the filter.

 

You've got do some troubleshooting.

When the bike's on the side stand; the oil level in the crankcase stays level and the sight glass gets above the level and looks empty. That's normal. If the level was still visible with the bike on the side stand ... then, it would indicate that there was entirely too much oil in there.

Since a number of factors depend on the oil and how much is in there; go ahead and drain it out of there. Then, with the bike on the center stand, refill the bike with the RIGHT kind of oil.
For what we need to find out; it wouldn't be a bad idea to get the right level of some 20/50 oil in there.

Fill it to the top line on the window.

Before you start it up; do the best you can to clean-up any mess that might have been made during the earlier running tests; especially inside the airbox. You'll have to pull the seat, open the airbox and clean-up the space ahead of the air filter where the other oil got drawn-up into the space.

After you clean it up good; put everything back to normal and you'll be ready to do a little testing.
+++++++++++++

Run it and warm it up ... if she'll go.
Look for smoke coming out the exhaust pipes.

Pull the rubber hose off the side case that vents the crankcase to the airbox.
With no intake vacuum pulling the crankcase gasses out; you should observe some heat escaping ... maybe a little bit of smokey exhaust -- But, NOT a high volume of exhaust or lot's of oil being splashed-out.

This test is going to reveal what's happening inside, with regard to how well the piston rings are sealing the combustion gasses on the power stroke. If the case is venting a HIGH volume of smokey, heated gasses and venting motor oil >> past the baffle, inside the case, just below the vent exit ... you'll need to do some further diagnostic testing.

Let's see what happens.
I'm hoping you were over-filled and maybe thinned-out bad from getting gas introduced to the oil supply.

I think we're all hoping that's the case for you.
With my fingers crossed and hoping this ain't going to get complicated.

Good luck,

 

ok, I changed the oil and it was extremly runny and smelled of gas giving me the indication that gas got in there. I pulled the carbs back out and cleaned them once more because there was oil residue from the previous oil spitting problem. I then took all the spark plugs out and cleaned the tips and tested for spark. Everything there came back fine and there was a small amount of oil residue on the plugs. I then put the carbs back into the bike - they are spotless now - and then cleaned the airbox and removed the exit hose from the box as advised. I went to start it up and nothing... wont go. The starter is going but the engine wont budge, not even a little. I sprayed a bit of starting fluid directly into the carbs and it started, but as you can guess for only a second or 2 then it died.

I have verifed that my fuel line is good, the carbs have gas in them. All parts of the carbs function properly. The spark plugs are in great shape and the the wires are each producing visible spark using the old screw driver test. It has fresh oil - Yamalube.

I am so saddened by this. I took the day off work yesterday to ride and like I said, it wouldnt start so I did all of the above after reading these posts.

Not sure where to go from here. The bike has only 13k miles on it. the block looks in prestine shape. No fluids are leaking either.

I am just bummed out now....

 

This could be a simple case of being out of fuel. If the level in the tank dropped below the main setting when the fuel leaked into the crankcase then you are now out of fuel. Switch to PRI for about a minute and then to RES. See if it starts then and make sure the choke is on full.

 

when the tank is off and I set it to PRI nothing comes out but when set to RES it does. Is this normal?

 

No. Fuel should flow freely with the petcock set to PRI and no fuel should flow with it set to ON or RES unless the engine is running and pulling vacuum on the petcock diaphraghm. I would assume that the PO put the petcock back together wrong.

 

You were exactly right. I did what you instructed. It took me literally 1+ min holding the starter switch on. After 1 min I started hearing some activity. Normally I would NEVER hold it down for that long. After it popped, it ran like ass for about 20 min. I put some more sea foam and some 93 octane gas and about 10 min later it was running better. I then took it out for a ride and it was sputtering quite a bit. Went on a few more rides and suddenly as I was going, I gunned it in 2nd gear and BOOM, something happened and it was like a new bike. Ever since tonight it has started right up no problem and is running excellent with no oil/gas leakage. I think it could probably use a full tune up but not sure if I really need to pay $90/hour for a shop to do whatever it does.

At any rate, thank you for helping me learn even more. 1 week ago today I drove by that bike and thought "Wow, it would be really cool if I could have that..."

 

I imagine it's going to be awhile before you stop grinning, huh?

Good deal; Bro ... a running bike is lots more fun than broke bike.

Hit the road; again. Someplace where you can really push some of that good gas and additive through there ... real good!

You want to get the bike up to 45-hundred - 5-grand on the tach and just hold it there for a few minutes. Be prepared to have her jump-up some more if the gas and additive clean-out more fuel metering ports in the carbs.

If she behaves nice and steady after blowing the good gas and additive through her for, like ... 10 minutes ... well, then ...

You are cleared for Take-off ... see how she likes 7-Grand!

 

And the only thing better than a running bike is a brok bike YOU got running! Congratulations and glad we could help!

 

My 85 XJ700XN does 70mph at 4500rpms... at 5000rpms, I'm doing 80mph. I've never taken it higher than 6500rpms (doing nearly 90-95mph at 6500). How the heck do you safely test anything at 7k?

Is 4500rpms/70mph normal? That seems a little low, considering how I have been hearing people talk.

 

Well ... I didn't mean to suggest that you should run the bike up to 7-Grand and HOLD it there.

I guess I should have been more precise.

Once you think she's running real nice; head-out for a little ride on some highway that has a nice run of an entrance ramp. When you get to the spot where it's time to wrist it open and get that baby movin' up to speed ... push second and third up to 7-Thou and "Blow it out" (NOT to be confused with 'Blow it up!)

A few sprints. up toward the fun-end of the tach, is going to let you know she's got it -- when you need it -- and, will do you both some good.

The bike is gonna suck a high volume of High-test and cleaning additive through every little place and get her heart racing for a few seconds.

You're going get to run through the gears in a blur; get the feeling like you were just shot off a flight-deck ... and, get YOUR heart racing for a few MINUTES!

Show her the whip. Rip through the gears unleashing the power within and just sigh "Whew" when it's over!!!

 

Hell yeah!

I am thinking about doing that tonight. I was quite happy with my ride last night giving her some juice but only up to about 50mph. I then ran out of gas cause I am an idiot and forgot to check my level. Does that sound normal anyway? I had a little splash in the bottom of the tank and there was still some gas in the fuel filter but she wouldnt start. Had to call the wife and she was pissed and brought me the gas can. Put about half a gallon in, cause that's all I had, and she started right up. Needless to say, I will always be checking my gas before heading out to back roads!

 

My breather tube is shooting out copious amounts of what looks like oil, if my crankcase is overfilled....how do I know? And how do I empty it?

My bike will shoot out oil gas mix from breather tube when it runs. Leaks out an insane amount when bike has fresh oil

 

Do not start engine again until you fixed your floats and then your petcock. And drain the oil, youve got a sump full of gas!

 

Beneficiall has a thread running on this issue. http://xjbikes.com/Forums/viewtopic/t=43363.html

He's been told these same things already. He apparently didn't like the answers he got; this is the third old thread (2006 again) that he's dug up and asked the same question over again.

Beneficiall: DUDE, YOU HAVE A FLOAT PROBLEM. Asking over and over and over again in multiple 7-year old threads is counterproductive. Especially since you get the same answers: FLOATS!

Your full answer is in your original thread on the subject. http://xjbikes.com/Forums/viewtopic/t=43363.html