Power valve cleaning and adjustment

[Matt Clark]

Today I spent some time taking apart my rotax to get familiar and when trying to remove my power valve, I attempted to "unscrew" the bellows by rotating the plastic nut on top. This made the power valve come out from the engine more, but eventually I figured out I had to remove the two screws on either side and take out the whole assembly.

My first question is, when people talk about cleaning the power valve, what exactly do they do to clean it? Secondly, when I re-assembled the power valve in the engine, I noticed that if I tightened the plastic nut down too much, it would cause the valve to stick on return after I had manually pushed it in. What is the proper adjustment for tightening this? Should I just get it as tight as possible without it sticking? Thanks guys.

Matt Clark

[Chris McGinley]

This link will give you a good general overview of the PV cleaning and re-installation (even though the pictures are the old style PV, the concepts are the same) http://www.karting.co.uk/KandK/Tech/RotaxPowerValvePrep.html

As for the "sticking", you definitely want to get that resolved. Make sure you put the gasket in correctly with the vent hole aligned with the hole in the PV housing and ensure you installed the blade facing downward. If those are good, then you may need to loosen and re-align the housing. Sometimes you may need to wiggle the plastic cap a bit (use a 10mm wrench) to help ensure the blade is aligned properly with the opening in the cylinder.

If you have someone at the track that has a Rotax and seems to know how to maintain their motor, you should ask them to give you some pointers if all else fails.

The Rotax can be a bit frustrating at times, but once you get used to its nuances, the general care and feeding is pretty easy.
_________________
Chris McGinley
Monster Raceworks
Rotax Masters
"Always stay one step ahead of the storm" - JZS
http://www.njkarting.org
http://www.btbsecurity.com

[Matt Clark]

Thanks Chris, I didn't get to clean it yesterday due to not having carb cleaner but got to it today, ended up screwing on the plastic nut as tight as I thought was safe without stripping the plastic and it slides in and out like a dream. I happened to find a video that I watched earlier today which was helpful for a beginner like me so I'll post the link in case anyone has the same question and wants to see it:
http://vimeo.com/36795487

Matt