I have a 1987 LT 500r and was wondering how much the power valve should rotate on its axis? 5°,45°, 90°? I know that at 4500rpm the power-valve should rotate seen though the sight glass on the jug. I have seen virtually no movement. The quad is not sluggish just a little raspy at the top end. This leads me to believe that the power valve has little effect on performance. It doesn’t make sense to me. I would think it would run like crap. Any comments are appreciated. Thanks

 

4X, The mechanism will rotate approx 90 Degrees when it does actuate... I don't remember the actual RPM, but I know it's up there (about 5,500 RPM I think).
There is an extensive explaination of the different power valve configurations here:
http://www.offroadhaven.com/powervalve.htm

The LT500 uses the SAEC setup. You may be in need of adjustment if yours isn't working.
They do have a tendancy to gum up if you're not using a really good quality oil.
This may require disassembly and a good cleaning to make it work the way it should.

Hope this helps.

 

I've had to replace the power valve governor assembly on my 87 zilla. The shaft had broken and the ***** were scatered. Also had to replace the thin spring on the other side of the jug.

87 Zilla
87 QuadSport