mystery black box

what is the purpose for the black plastic box to the right of the carb, that the crankcase vent lines route into? Can this be removed without detriment? It's sure in the way for easy carb access and it would sure be nice to remove...

Thanks, Troy

many people here have removed it, you could do a search and see what they have said.

or you could just go from what I've found out:

-removing the black box will do nothing really, maybe even harmful if you don't do it right.

-it prevents you from rotating the carb

-I believe it was put on there for the nature nuts or something

I decided to leave mine on, I rejetted by taking the whole carb off (didn't find this hard at all). After all, how many times do you plan on rejetting? :)

TT, The black box you are talking about is a vapor/oil separator. It allows the blowby gases to escape to the atmosphere and any small amount of oil to be returned to the crankcase.I would leave it on,you won't notice any preformance gains by removing it.

I agree with leaving it alone. At 10,000 rpm there is a lot going on in that engine and it needs to equalize and breath without taking in dirt. I know not much is happening now. But after a few years and lots of miles it will be more of a factor. If it was just the S model I would be suspicious but the dirt only models have it to. I'm sure the debate will continue. Time will prove which one is right.

Ditto EZGZ,

Crankcase pressure releif is very important especially when reving. It would probably result in a performance loss. (Roadracing trick is to have low pressure).


You've heared it,

there is no real advantage of removing this black box.

some may argue and say:

easier to work on the carb- ( i only remove my carb once a year, maybe)

weight saving( not)

more air to the rear shock, cooler operation(I don't buy it)

some people removes the box and runs straight hose to vent the crankcase gasses( like yamaha does) but you will end up with and oil dripping on your frame and garage floor.

some people use the "T" and run rubber hoses to eliminate the box, why go through the trouble when it is just fine the way it is.

I removed mine a while back, but eneded up putting it back on.

It is fine I say leave it on.

Tips of the day:

learn to Enjoy what you got!

don't compare it to other bikes, if you would have the other bike, you would dream about a different one anyway.

Enjoy it while you can !! :)

[ December 19, 2001: Message edited by: Zsebi-2 ]

I removed mine and Tee'd the hoses together. It took about 2 minutes and $2. Now when/if I work on my carb I can rotate it. And if/when I break a throttle cable, I can get to it easily. For the small amount of hassle and $$ why not get rid of something that isn't really serving any purpose. Yamahas have the same blow my line that runs straigh to the ground, no box to catch it. That's the way my DRZ is now. My overflow line ends just above my chain(below my airbox). I think of it as chain lube on the fly. :) Unless you plug the line, the crankcase is still vented. There is absolutely no power gain or loss from Tee'ing the lines together. I would not plug the line. The vent is there for a good purpose...the box is not.

[ December 19, 2001: Message edited by: CAL ]

Granted, I am talking about my "s". But my dealer would not pass inspection with it off. I ended up putting it back on...Like mentioned. Other than gaining a bit more room to work, I saw no big gain from removing it.

I took it off and installed two small K&N crankcase breather filters and zipped tied them up so they did'nt hang. Bike breaths great and easy carb access.

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