Some engineer on the klx300 design team calculated the blow by on the rings and calculated an opening diameter that would prevent the build up of pressure wot with crappy rings.....a guesstimate.

There diameter picked....it is not performance based decision, its maint based...preventing buildup of pressure reduces likely hood of oil leaks.


Perhaps later someone looked at the diameter guesstimate and said wtf was he smoking it does not need to be that big and then it was smaller.

I'm an engineer...we do that sheet all the time.

 

I kind of like the idea of the one-way pcv valve which actually maintains a slight vacuum inside the crankcase on the upstroke instead of a bi-directional vent to atmosphere. I put one of those on my current bike. I sure can't tell any performance difference, but knowing it's there makes me feel better.

 

I don't know NoBrakes, I would think a slight positive pressure would be better than a vacuum..... only because if my bike had a slight oil leak and I was doing a water crossing that vacuum could help migrate water and other contaminates into the case.

Small positive pressurization amounts do have their merits...like keeping the outside stuff outside.

 

Pros and cons either way. Six in one, half dozen in the other. Maybe its best just to leave the dang thing alone and go ride instead.

 

lol....I miss Iowa, he lived for this carp.


Just got our first cold front...woooo hooo it may get below 70

Taking tomorrow off work, hitting the scrub wot on the adv in her stripped down lc4 enduro version....going solo so I got an EPIRB in the backpack in case a tree does not move.

 

The ball in a pvc valve can't react quick enough to the changes in pressures, it'll be open when it needs to be closed etc. Bike motors that utilize this kind of vent control use reed valves (ducati) or some kind of timed mechanical driven device (H-D).

 

I remember hearing that enlarging the hole would give better throttle response.

 

Yep, so we all blindly enlarged it.