EVERY ZS250 OWNER TAKE NOTE!!!!!!! "911"

[Namikuz]

Well we now know what happened to my engine to cause it to hydro-loc. The crank case vent tube that goes to the air box, under the carb area, was mis-routed
 and pinched, allowing the oil to fill the tube and virtually pump the oil in to the fastest part of the inlet air stream. NOT GOOD!!!!  Just the possition of this hose is a bad design. You should NOT put a hose from your crank case to a VERY high velocity port on an air box. Where the hose enters the box, the box reduces in volume and makes a turn towards the carb. This creates a venturi effect (sort of) and siphones oil from the crank case at hi speeds.
So make sure the hose is NOT folded over by the framing near the airbox.  I am going to be altering the location of this hose.
Details to follow (with pics) once I get my 'lil Pak Mule back.

[250gs]

Not sure exactly what you mean but it sounds serious. Let's see your pics!

[cbyerspace]

from what I hear this is one of the main issues with the design, I myself am going to head out to an auto parts store and pick up a breather filter and just remove the tube and give it its own stand alone setup... and you shouldn't have the problems in the future...

[saint3570]

please let me know what set up u think can work with these bikes and are there any adjustments to be made after installing one of these stand alone set ups or is its a plug and play sort of set up?

[cbyerspace]

It is a very easy mod, All you do is remove the tube that goes from the crankcase to the air box and slide the breater filer on you do have to plug up the air box where the connection was... As far as knowing what to get its just a breather filter the one I got was for sizes 3/8"-1/2" and it fit perfectly and they only cost about $10 at pep boys...

If your not sure what hose Im talking about its the one that is where my filter is, you may notice I don't have a clamp on it, Its so tight of a fit it really doesn't need one, but mainly its because it was in my way...

And I did have a good half a quart of oil in my airbox... I found it when I went to modify the air filter (which is also easy) and it blew my mind...

[z250gs]

It's a good mod if u really need it but i'm still not convinced that this is anecessary mod. I would first be checking that the oil level is correct in the sump .If you really find that much oil in the airbox then you'd be continually topping your oil up in the sump  as the oil level would be below the Low mark on the sightglass window.  When the bike is leaning on the side stand you can't see any  oil in the sightglass window. If you can then you've overfilled it. You have to pull the bike up dead vertical to get a proper level reading.

I was reading a few other forums that mention  other problems that can result from too much oil in the sump  such as frothing of the oil and  premature gasket failures. 

So it may be worth checking your oil level first before doing any mods to the breather.

[cbyerspace]

of course I just bought the bike acouple days ago the dealer had put to much oil in (which is making me have to do an oil change)... But even after the oil level is right the airbox can still create a vacume effect, which can cause small amounts of oil to be pulled up and I would rather not have any oil in my airbox.

but you are very much right Be sure to check your oil with the bike straight up and down, My dealer didn't even know that, and he has been driving his for around 6000 miles with too much oil and every time it would go down to the proper level he would fill it back up, He found out that he had been doing it wrong when I spoke to him today (I guess most beginers don't know that so nobody ever noticed)...

[saint3570]

thank's guys  for the info on the breather, the picture really helps  now how would i plug the hole on the air box? and i dont have a maintanance manual how do i get to the airbox do i have to remove the seat?
 

[cbyerspace]

Yeah its a pain getting to the airbox or battery, You have to take off the seat and the whole side panel, The air box is on the left side when sitting on the bike and the battery is on the right... When you take off the panel there is a screw under the mud flap thing It wont come out without removing that and you don't need to completely remove it, just have it move away enough to get a screw driver and wrench under... and if its your first time removing one of these panels there is a part that just pops in and out without screws so if it catches thats normal just wiggle it out....

If your going to mess with the air box there is alittle clear plastic tube sealed shut clamped on, take it off and that will drain any oil you have in the airbox, make sure to put the piece back on after. As for the peice you need to plug up anything that will seal it possibly even duct tape but that is a temp fix, I just cut the hose shorter and caped it off.

[cookac]

From my experience dealing with the hose coming out of the crank case, it seems to be important. That hose is also tied in with the air valve which creates the suction to take heat out of the engine. Removing that hose might possible not get the heat out of the enigine as efficiently. That is my opinion and understanding of those hoses.

[cbyerspace]

its puropose is to relive oil pressure... even if you don't have a filter on it still does its job but i sugesst alteast puting a breather filter on so you don't get crap in the motor... but yeah, thats all its there for the reason it is fitted to the air box is to follow emissions requirements... like if you live in cali this mod may not be doable because of law in some parts... but all in all its like changing your exhaust you can in some areas and others you just have to deal with it...

[cookac]

Ok yeah that makes since now. I found out those hoses connect to a carbon filter which is part of those emission standards. So yeah filter prob is a good idea to stop oil.