PV adjustment?

Sorry for 2 PV threads but I didn't want to piggyback off the current one and potentially hijack it  :thumbsup:



Whenever I have done a top end on a bike, I have just taken the PV apart, cleaned it and put it back together.  Is this ok and common practice amongst the majority?  I've heard of people adjusting the flux capacitors in there to change different X, Y and Z dimensions but I don't know what to do, if it's worth it, if I have nothing to worry about doing it the way I have been doing it.....or if I'm all jacked up  :excuseme:

X dimension refers the distance from top of piston to top of cylinder, nothing to do with PV


Z dimension refers to the PV setting, how far from top of clinder when fully closed. This should always be set. ( IMO to stock.) If you do not loosen the adjustment screw when disassembling then you don't have to worry about it.

You are doing fine as long as you are not touching the PV adjustment stop. Depending on your jetting and premix brand and ratio, you may not need to take the PV apart. My last 5 top ends looked clean on the PV with no sticking at all. I lowered the Z height the first time and have left the adjustment alone since. When I bought my 250 used, it needed 30 minutes on the wire wheel to get the burned oil and carbon off the PV and some real effort to clean the cylinder. 

I run 44:1 for a little extra lubrication for fast valley crossings.  I always have to clean up my PV a bit.  Thanks for the info guys!  Any youtube videos out there that demonstrate this?

 Any youtube videos out there that demonstrate this?


Go to Slavens Racing, in his videos section there is one for taking it apart and one for setting the Z dimension.

Jeff Slavens is one of the best KTM tuners around and is more than willing to share his knowledge. If you ever decide to do a suspension refresh, Jeff is also one of the few suspension experts that shows how it is done  rather than just charging a fortune for basic work.


Power valve service KTM 250 & 300


http://www.youtube.com/watch?v=EwSnE04l9Zo Part 1


http://www.youtube.com/watch?v=RCoJQE-xw1w Part 2


http://www.youtube.com/watch?v=AvLUSh_nHbY   Setting Z height


44:1 is reasonable as long as you are using a clean burning synthetic oil. Some oils burn much cleaner that others with equal lubrication, so if the PV is gummy it may be worth researching some other options.  

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