This Crankcase Vent Mod. will use the vacuum supplied by the exhaust through the reeds to create a negative pressure in the Crankcase.
This helps the internal parts do their “work” without the resistance of positive pressure.
The engine is more efficient with the pressure drop.
This mod. should help your engine rev. faster. HP gains? Depends on flow. I have not "yet" measured cfm on the 10.
How the Air Switching Valve works. I cut this out of the 08 service manual and inserted some text. May be useful to help understand what happens here.
1/2" T and 1/2" I.D. 5/8" O.D. hose replaces the stock components. Our vacuum supply.
This pic. is a screen shot of the crankcase vent line (highlighted in Green) from the service manual. This is the crankcase vent hose.
Here you can see an inside view of where the crankcase is vented to in the 08 airbox. Does the crankcase have positive pressure? Notice the small amount of oil circled in black.
Here you have your vent line disconnected from the airbox (circled) and the new line fits right inside. Reuse the same pinch clamp.
Airbox nipple gets a 1/2 - 5/8" I.D. cap and can be returned to the stock setup easily.
I routed the new vacuum line on the right side to avoid the already cramped fuel line on the left side.
Obviously, connect the vacuum line to the 1/2" T
When the mod. is complete it looks something like this.
I used about 3ft. of hose, one 1/2" Tee, two 5/8" caps (I think 1/2" caps would work) and 6 stainless hose clamps. Cost around $5.
Flowtest vid. on page 6