It would make sense to me to just remove the crankcase vent from the air box like miykl said. You will gain positive pressure in the airbox and you keep ram air pressure from entering your crankcase, thus letting your crankcase "breathe" better. I don't know if their is a check valve in the crankcase vent or not.
Pulling a vacuum on the crankcase will aid in ring sealing, but you are not going to see it with the KLEEN valve on the 10. It just does not pull enough of a vacuum to be able to do this.
Most race teams that do this, ie nascar, indy, and maybe the drag racers are using a dedicated vacuum pump plumbed thru the pcv syystem. I ahve yet to see a true vacuum system on any of the major bikes in any form of racing to do this yet.
I would much rather get rid of the extra crap and make the engine bay cleaner than deal with the crap from the KLEEN valve. Someone had a dyno graph with before and after runs with this mod and it does absolutely nothing for power on the 10.
I think I will have to agree that there will be almost no gains to doing this on the 10. I did this mod on my 12 back a few years back
while I was visiting the 12.org site and a few guys on there said it gained between one and two HP.
Yea, after I thought about my post above, I remembered the Suzuki GP bike had a vacuum line connected to the oil fill cap. For some reason I had pressurizing on the brain.
The Suzuki definately had a dedicated crankcase vacuum line.
NHRA Pro stock motorcyclyes use a dedicated vacuum pump and they pull somewhere around 20-30 in. of vacuum. I don't think the Kleen mod will make a difference but it don't hurt either. Here is a pic of the main pump that the NHRA PS Bikes use and just FWIW the pump is $2000 or was it $2200 but with the lightweight motor I know is $2700.
I dont think their is any real benefit except that the air isn't being put into the crankcase. I can only assume that the crankcase is supposed to vent into the airbox whereas to burn up the air from the crankcase (ie: fumes from unspent fuel and oil im guessing) This will be done for the emissions. I also will go as far to say that it will probably benefit from removing it from the airbox but if you go that far you may as well hook it to the Kleen ports on top of the valve cover. If you don't do that and just remove it from the airbox you do need to add a crankcase filter so it doesn't suck in dirt and grime from the road.
Both my 12R and 10R have this done. On the 12 in back to back dyno pulls it made 4Hp. The dyno operator nearly shit himself and continued to make pulls just to be certain of what he was seeing. I haven't pulled the 10 yet with this mod but when I do I'll let you guys know. You have to disconnect it to tune the FI because the sniffer don't like the oil mist. So before I take it off the pump I'll rehook it and pull again like I did the 12.
This has been argued about on every forum I've ever seen. Lots of guys on gixxer.com tried it. Like others have said, you don't get enough of a vacuum to produce any "actual" hp. Some people say they get an extra horse or whatever. But that is almost always due to something else or just the fact that dynos rarely say the same thing twice.