As stated above, don't wait more than 1000 miles. I actually prefer to do them every 500. The razor/scotch brite - dipped in carb cleaner works good, but I also found a small, fine wire brush on the end of a drill works the best. Be sure to put some lithium grease on and near the o-ring on the shaft of the valve before inserting it back into the housing. Also, don't forget to clean the inside of the housing (on the casting of the cylinder) with Q-tips dipped in carb cleaner. It's just as dirty in there as the valve itself.
Once put together, adjust per the manual. Every thousand miles, I'll take the exhaust manifolds off and feel if the adjustment is correct by reaching inside to feel if the valve is flush and or fully opened or closed. You'll either have to have the power valve tester or as I do, I rotate the valve motor by hand to it's open position (I have it marked with white out) and feel from there.
Cheers,
Jon
