Valve Cover Block off Plates / Crankcase Breather ?

jboyd12 · March 28th, 2012, 10:25 PM

Is there any advantage to using block off plates like many people do to the 600 bikes? I was thinking about capping this off. I know many people do it on the zx6s to get rid of the emissions stuff to get a more accurate air fuel ratio. But it looks like this is just putting hot air from the valve cover into the airbox. If I cap this off, will it be beneficial or harmful?

Now my Crankcase breather question:
Theres also a hose coming off the crankcase to the airbox. I was wondering if I disconnected it from the airbox and used a smaller filter for itself could it be more efficient and potentially increase power due to lower air temps?

photo (12).jpg

photo (13).jpg

photo (14).JPG

headshrink · March 28th, 2012, 10:34 PM

Several of us use a block off plate. I did it mostly to minimize the junk and a plate is nicer looking than just plugging it. There is no noticeable difference in performance, at least as far as I can tell. Supposedly this was a solution to some decel popping for those who didn't want to really get in and re-jet after modding their intake.

As far as the little filter on the crank case, I have no idea; but I imagine it would make even less of a difference.

jboyd12 · March 28th, 2012, 10:39 PM

Thanks for the info, but one more quick question:

Is this supposed to be open like that?
It seems like there should be something connected to it..
photo (14).JPG

quanttrom · March 28th, 2012, 10:46 PM

mine is open just like that

headshrink · March 28th, 2012, 11:37 PM

I don't remember, but I think it was open also.

drvr5 · March 29th, 2012, 08:57 AM

Yes, that's supposed to be open.

Any performance gains you get from filters/blockoff plates would be immeasurable- but the theory is sound, so go ahead and do it anyways. If there isn't a reason you're keeping the stock air box- k&n r-0990 pod filter makes a noticeable difference through the whole power band, and is about $30. Shimming needles is required, rejetting is highly suggested. Both of the mods you are talking about are required when switching over to a pod.

March 28th, 2012, 10:25 PM	#1
jboyd12 ninjette.org member Name: Jen Location: NYC Join Date: Jan 2012 Motorcycle(s): 2010 Kawasaki Ninja 250 Special Edition Posts: 95	Valve Cover Block off Plates / Crankcase Breather ? Is there any advantage to using block off plates like many people do to the 600 bikes? I was thinking about capping this off. I know many people do it on the zx6s to get rid of the emissions stuff to get a more accurate air fuel ratio. But it looks like this is just putting hot air from the valve cover into the airbox. If I cap this off, will it be beneficial or harmful? Now my Crankcase breather question: Theres also a hose coming off the crankcase to the airbox. I was wondering if I disconnected it from the airbox and used a smaller filter for itself could it be more efficient and potentially increase power due to lower air temps? photo (12).jpg photo (13).jpg photo (14).JPG

March 28th, 2012, 10:34 PM	#2
headshrink ninjette.org certified postwhore Name: Bob Location: CA Join Date: Dec 2008 Motorcycle(s): '08 Ninja 250r, '14 CBR500r Posts: A lot.	Several of us use a block off plate. I did it mostly to minimize the junk and a plate is nicer looking than just plugging it. There is no noticeable difference in performance, at least as far as I can tell. Supposedly this was a solution to some decel popping for those who didn't want to really get in and re-jet after modding their intake. As far as the little filter on the crank case, I have no idea; but I imagine it would make even less of a difference. __________________________________________________ Honda Interceptor VFR800 DLX (2014, 8th gen) Honda CBR500r (2014) - FOR SALE Kawi Ninja 250r (2008) - Restored and passed-down within family, only to be abandoned

March 28th, 2012, 11:37 PM	#5
headshrink ninjette.org certified postwhore Name: Bob Location: CA Join Date: Dec 2008 Motorcycle(s): '08 Ninja 250r, '14 CBR500r Posts: A lot.	I don't remember, but I think it was open also. __________________________________________________ Honda Interceptor VFR800 DLX (2014, 8th gen) Honda CBR500r (2014) - FOR SALE Kawi Ninja 250r (2008) - Restored and passed-down within family, only to be abandoned

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March 28th, 2012, 10:39 PM	#3
jboyd12 ninjette.org member Name: Jen Location: NYC Join Date: Jan 2012 Motorcycle(s): 2010 Kawasaki Ninja 250 Special Edition Posts: 95	Thanks for the info, but one more quick question: Is this supposed to be open like that? It seems like there should be something connected to it.. photo (14).JPG

March 28th, 2012, 10:46 PM	#4
quanttrom ninjette.org member Name: QUANT Location: Canada Join Date: Jun 2011 Motorcycle(s): 250r Posts: 176	mine is open just like that

March 29th, 2012, 08:57 AM	#6
drvr5 ninjette.org member Name: Carl Location: Phoenix, AZ Join Date: Apr 2011 Motorcycle(s): '09 250 Green+Black Special Edition Posts: 19	Yes, that's supposed to be open. Any performance gains you get from filters/blockoff plates would be immeasurable- but the theory is sound, so go ahead and do it anyways. If there isn't a reason you're keeping the stock air box- k&n r-0990 pod filter makes a noticeable difference through the whole power band, and is about $30. Shimming needles is required, rejetting is highly suggested. Both of the mods you are talking about are required when switching over to a pod.