K & N filters

[HansO]

Some had PCV valve in valve cover going into intake behind carb

they must have had some form of restriction as you would not want a negative vacuum in crankcase, you aren't thinking of the vacuum hose for the vacuum power assist brake booster which did feed of the inlet manifold? I just don't recall seeing a PCV feeding into the manifold ...... maybe I'm just getting to old to remember

 

[Fingers]

We used to pull the PCV valve cover to get customers to pass emission tests it would suck fresh air in and would burn cleaner, but who really cares you do not think it is a good idea I 'lltake your opinion as you have more experience with these bikes than I. (Should be pull PCV valve out of the valve cover) brain thinks faster than I can push keys sometimes

 

[Rocket Scientist]

The crankcase inlet was in the air breather with its own little filter. The PVC valve generally plugged into one of the rocker covers and went to the carburetor above the throttle plates I believe. I think some went straight into the intake.

 

[HansO]

I personally think it is great idea (and will get around to doing it myself one day) but would like to share between all three cylinders (advantage of Ramair filter), I personally think the little K&N is OK except that it leaves a oily mess on the lower back of motor which attracts dirt making it a Horrible Dirty Oily Mess.
IMO I doubt it would ever block up as the out going oily fumes wash any dirt attracted to it down the back of motor