puking oil out the airbox

[kf4anm]

i had my xj out last sunday. it had sit for a few weeks due to the weather. it was a bear to crank but when it did it seemed to run fine. i made a couple laps in the neighborhood to warm it up then out onto the street. as soon as i got on it it choked and died. the only way to get it to resart was under full choke and throttle. when it would crank it smoked like the james bond astin martin. needless to say i pushed it about a 1/4 mile back home. i tought i had ran it to low on gas and picked up some gunk or moisture. today i pulled the tank, checked everything, replaced all the fuel and vacuum lines, and installed new filters on them. the bike would turn over and but not catch. after a few backfires and one small fire in the airbox i opted for new plugs. it hit on the first shot and ran great. it idled fine and the suzuki vacuum system was delivering fuel perfectly. once again a few laps around the block, thing were fine. soon as i hit the street it choked and died again. i managed to coax it back home. when i got off i noticed a pretty good puke of oil goming steadily out of the airbox. i'm pretty sure i blew a seal somewhere. anyone have any suggestions or opinions where to look. other than the tran this bike has ran great all summer. we will be pulling the motor to fix that hopefully in the next week so i will be free to do what ever motor work is needed.

thanks daryl

[fusionking]

Chances are your needle valves let gas into the engine while setting. With your bike on a level surface on the centerstand check the sight glass. This is a common malady on this motorcycle. If so change oil and filter. This is the very reason the PO sold me my bike. He thot he needed to build the motor also. All I had to do was change oil and go!!! Sure can't hurt to check!

[kf4anm]

oil

i thought about that because my xj came with a dorked up fuel cock system. i just have never encountered the oil coming back through the carbs to leak that way. i did notice the plugs had a gasy smell to them when i changed them. i just dont understand how it could run fine for a few minutes once i changed plugs then start. possibly because the motor was cold and i was getting fresh gas to the carbs but once it warmed up the oil with the old gas drained into started to circulate and since the gas has diluted the oil and caused it to overflow its normal capacity i started to get the smoke? (just a guess there). once i change the oil should i change plugs again or would a good cleaning be ok? i have 2 fuel shut off on order at napa that should be in tomorrow, between that and finally getting the vacuum system right i am going to elimate the problem once and for all. thanks for the reply and the info!

daryl
"knows his batteries but is whizzing in the wind every where else!"

[TheDjost]

My guess is that Fusionking got it on the money. the extra fluid in the crankcase makes the contaminated oil overflow in the airbox through the crankcase breather hose when you take off at higher speed / RPM. Take the breather hose off and temporarily route it in a small plastic botttle with old rags in it. Keep it vented up top, but make sure that if any oil gets in is stays in. That way you will know if the breather is the source of the oil in the airbox.

-Justin

[TheDjost]

I forot... You will need to change the spark plugs also if they have been contaminated with oil. You can clean them and keep them as spares, but I would not use them unless I REALLY had to.

-Justin

[kf4anm]

oil

i went back out for a second look after my blood pressure returned to normal. i pulled one of the new plugs and it was covered in oil. i'll grab a new set. oh well 7$ for about 15 minutes. the oil level did look kind of high in the sight glass and when i opened the filler cap it was pretty fumy of gas. i could see the oil with my light and it had a milky diluted look to it. i will drain it before we pull the motor to change thr transmission and go from there. hopefully that will take care of it. i should have known the gs850 i just bought has the same disapeering gas problem. thats why i got it for a song. a pair of forcepts on the line solved its prob. thanks for the info.

[motorbiker69]

yes i belive this maybe the problem.i had a gs 1000g(what a pig dog)that done the same thing(fuel in the crank cases),however i've never had the problem on my 1.1"s.

[kf4anm]

oil change results

friday i got a chance to spend some time with the xj. i ran down to autozone and grabbed some cheap plugs, oil and filter. nothing fancy i just wanted to get it running before starting work on the transmission. (one major problem at a time). when i pulled the filter basket about two drops of oil came out. i took my flashlight and looked in the oil filler hole and it was slap full. i wiggled and jiggled the bike even hit the starter to change the compression stroke thinking maybe i had an air or vapor lock in the crankcase. nothing, finally i stuck a siphon in the crank and let it flow. i pumped 7 quarts out of there. it almost overflowed my oil catcher. after i got it out i put on the new filter basket i picked up. ( the po had taken a chisel to the original and eat up the nut) put in the plugs and oil. took the precaution to install the new fuel filters and shut off valves i picked up at napa last week. put in some gas with a little seafoam and let it rip. it fired pretty easy and seemd to idle fine. it smoked for about 5 minutes. i guess it was burning off what little oil was left in the carbs. i pulled it down to the street and was getting ready for a test ride when it started surging. about a 5000rpm swing. after a few minutes thinking i pulled the new filters off and that cured the problem. i guess they weren't flowing well enough. i made a couple of passes around the block and it felt good. i hit the street and it stumbled a little in second. i made another pass, cranked it and she done what she was supposed to. problem solved thankfully! the end of the story i went in to change my clothes to take a real ride, saw a flash of light then heard the thunder. then the bottom dropped. i heard my neighbor crank his xj to put it up. i just got mine in the shed before it really let loose. thanks mother nature i spent 8 hours working for 10 minutes ride time.

[fusionking]

Nice Neighborhood!!!!!!!

Your neighbor has an xj?? Sheeesh

[kf4anm]

neighbors

oddly enough we both had 79 kaw sr650's also. however he sold his then regretted it so i sold him mine, freeing me up to get the gs850. he has had his xj for a while and has it looking pretty good. it was the main influence on the purchase of mine since i knew he had experience with them already. i just sent in a pic of mine last week. i have one of his i'll send also.