I have a 03 z400 and am stumped on what that cause of my problem is. there is a little black air box that is next to the main air box and it has three hoses coming off of it. one from the case, one from the valve cover and one to the air box. i have called many dealers, which only want me to bring it in for business, and no one can give me an answer. I rode my quad, ran fine for the first two hours, took a break, went to ride again and ran like ****. my swing arm had some oil on it, leaked from the hole in the bottom of the airbox and my air filter was caked in this oil.

what i think: i think its getting oil shot up from case into air filter and choking my quad out. oh and when it was running, i had blue smoke, kinda like a two stroke [img]i/expressions/face-icon-small-smile.gif[/img] haha. i am guessing that is from the oil that is being thrown into the carb. one guy said it might be bad rings, which it just had a big bore kit installed in last season and was broken in or maybe valves, which i have checked. please help me.

 

Those black PCV boxes hold oil, and if it is leaking or broken you will get oil in some strange places...... there was actually a TSB from Suzuki about these back in 2005 and your dealer should know about it. The TSB was about the oil leaking from the bottom and onto the engine..... I actually had mine replaced about two weeks after I had it as I noticed oil was showing up on my clutch cover......

I suppose depending on where yours is leaking the oil could be going to different places, but I'm not sure why it would be running crappy unless you are sucking oil into the intake or something.

 

i know, i ran into the dealer ship, no recalls for mine and all he said is to bring it in to him. I think it is getting sucked into the carb and thats why its blowing puffs of smoke and is running to rich. i guess i dont really know what that whole thing is on the inside. can it go bad? My air filter is soaked in the oil that is coming back through the case i think and up into the filter. i have gotten the response, "are you sure its not over filled with oil". i just changed it though. i guess why does it hold oil and what does it hold oil for? how does it work?

 

when my quad did that it blew the top end. the cylinder sleeve cracked and blew oil everywhere and it was only a year old

 

<div class="FTQUOTE"><begin quote>Originally posted by: hondarider416

i know, i ran into the dealer ship, no recalls for mine and all he said is to bring it in to him. I think it is getting sucked into the carb and thats why its blowing puffs of smoke and is running to rich. i guess i dont really know what that whole thing is on the inside. can it go bad? My air filter is soaked in the oil that is coming back through the case i think and up into the filter. i have gotten the response, "are you sure its not over filled with oil". i just changed it though. i guess why does it hold oil and what does it hold oil for? how does it work?</end quote></div>

It is just another part of the oil system. It is designed to let excess oil heat escape, it is just like a crank case breather on a car engine "PCV valve" or positive crankcase ventilation. The oil circulates through the whole system. Take a look at where the lines from the PCV box and the oil tank run and you can see how the system cycles.

When the z400 was still being used for racing, a lot of XC and desert guys would run a little more oil in the system than needed because there is a lot of room in that system and ideally a little more oil will last a little longer for those big long races.

 

its a crankcase breather. its supposed to let the oil that comes from the valve cover go back in to the case and let the case pressure go into the intake just like a PCV valve on a car. and if it gets to much oil in it then into the intake and the air box. and if it blowing oil out of the valve cover then its to much blow by from the rings

 

i was told that also that it could be rings and that it could be the cause of it, but when i road it, it ran fine for like two hours. perfect actually but than after like two hours, it acted up and started to want to bog down and thats when i noticed that there was oil on my swing arm, which was dripping down from my air box and was coming off of my air filter....can those black boxes ever go bad? what does the inside of it look like? was told to clean it out with solvent but a little hesitant since i dont know what is on the inside

 

<div class="FTQUOTE"><begin quote>Originally posted by: hondarider416

i was told that also that it could be rings and that it could be the cause of it, but when i road it, it ran fine for like two hours. perfect actually but than after like two hours, it acted up and started to want to bog down and thats when i noticed that there was oil on my swing arm, which was dripping down from my air box and was coming off of my air filter....can those black boxes ever go bad? what does the inside of it look like? was told to clean it out with solvent but a little hesitant since i dont know what is on the inside</end quote></div>

Yes the black box needs to be replaced...... as I said there was a TSB (Technical Service Bulletin) which your dealer should know about. A TSB is not a recall, it is just a "heads up" to Suzuki techs from the factory that this part is prone to failure....the seam on the box fails when the oil gets hot......there is nothing on the inside of it, but there is no point in cleaning it if it is still going to leak...... you can try and silicone the leak yourself but it won't last once the oil gets hot....

If it is leaking it needs to be replaced right away.....

 

does anyone know where i can see pictures of what the inside of that oil seperator looks like...and NOT the exploded view of a parts list? If oil comes from the top of that box and goes to the bottom and is suppose to "recycle" back into my engine, what would cause it to be filling up and coming out into my air box? the lines are not clogged and i did clean it out with some solvent. Has anyone seen one of these things cut open? Has anyone had this problem? I dont think its blow by and i dont think its my rings that are bad. i would bet on that.