I've been running an o-ring chain for 3 years / 10,000+ miles. Have yet to adjust it. Lube it 3-4 times per season.
I machined my existing sprockets myself. Take .060" of either side of the tranny sprocket, .120 off of the outside of the wheel sprocket. Machining only one side of the wheel sprocket will better center the chain on the chain gaurd.
HTH,
Derek