new member - getting alot of oil in the air cleaner box

My '82 XJ750 sat for several years. I'm guessing the crankcase ventilation system isn't working correctly. Any help or ideas appreciated. My next step is to remove the oil separator casting and check for a build up of sludge. Never done this before.

 

i just had this same problem start randomly on my '81 xj650.
I checked the crankcase ventilation hose and there is no sign of oil that has run through it.

All i can think is that i over filled the oil. But can't see any signs of oil running through the cvt.

 

There is not much that can go wrong with the XJ vent system. The passages are friggin huge.

you should see the oil fill line in the sight window on the bottom of the clutch cover. If all you see is oil, you got way too much in there.

oh yeah, check oil with bike on center stand.

edit:... a common problem with bikes that sat a while is that the carbs overflow with fuel because of malfunctioning float valves, and the gas just flows down into the crank case. If your oil smells like gas, drain it immediately.. also get ready to pull the carbs for a thorough cleaning.

 

this is defenatly oil in the air box and a lot of it in my case. I guess i could drain the oil and refill. Is there any where else the oil could be coming from?

 

+1 stereo.
If you didn't over fill the crankcasae with oil, one of the floats stuck open and filled the crankcase with fuel causing the oil to push into the airfilter.

Stereo, nice Frank reference on the other post. :wink:

 

this happened to me 3 days ago but I was working on and learning the bike. It happened to me because my vacume line was connected to the petcock (for the first time and I was unsure if the petcock was working correctly anyway) and the petcock was set to prime. I made it 2 blocks, the engine stalled and back wheel locked up. I looked back and left a streak of oil the entire last block, oil leaking all down the side of the bike right out of the airbox. rebuilt petcock, tested it with my mouth - set to ON and sucked and observed the fuel come out, and then ran the bike in the ON position and it was ok. if thats not it it's the carbs, but I know when the float levels / float valve seats go bad the gas goes in the case, but I don't know how that would bring oil Up. Is the oil in the 'site glass' over the top of the glass or is the level somewhere in the middle of the glass?

 

Okay that makes sence. I will look for a stuck float. I just cleaned and rebuilt these carbs like two months ago. I noticed that i was riding the bike for a little while with the petcock in the prime pos. still did the same thing in the on and res pos.
Thanks!

 

Well i'm kind of Jacking this tread but considering we have the same issue no sense in starting a new thread.

I checked the flow levels today and all were with in 1-1.5mm from the top of the float bowl. I pulled the carbs and all the floats seem to be operating well, and no build up or crud on them.

I did notice however the main jet needles seem to be sticking a little but this is kind of sporatic. would it be okay to clean the piston valve with some steel wool or a brillo pad?

I hope it is just one of the piston valve sticking, does that seem like it could cause the problem?

I also drained the oil and man oh man was there a lot of fuel in it. I pulled the drain plug and it flowed like water. It did however clean a lot of gunk from the inside of the motor out.

 

cleaning the piston and needle is very much ok. It's somewhere in Rickco's thread here http://www.xjbikes.com/Forums/viewtopic/t=2908.html
although I don't beleive that's your problem

 

So i went through the carbs again today. the floats are not sticking at all they move freely, they float in water, the little spring piston on the underside of each of the float jets is working smoothly, the valve pistons pass the clunk test. I just can't figure this out. I checked the level of the floats and they are all with in 1mm of the top of the float bowl. Am i missing somthing here?