For a friend of mine, needed some work so we made a deal that if I fixed it I could use it whenever I want and I've been using it alot, runs great after a new carb and intake boot. I've been using 10W40 wet clutch oil, which I think is Honda spec, I don't run it hard, mostly on trails, but I do like to open it up in 5th gear every now and then. Should I step it up to a 20W50 wet clutch oil, or would it be too thick? I'm thinking Valvoline Motorcycle 20W50....and should I stay conventional or go with synthetic? Was thinking Mobil 1 4T 10W40 or Mobil 1 V Twin 20W50 if I go with synthetic.