My '02 vt750 has 2800 miles on it and i am getting clutch slipping with the GN4 Honda oil (the red cap) at high rpm's when accelerating through the gears. The oil has about 1000 miles on it. The slipping is very minor and only does it when really going through the gears fast. It is a weird feeling. Almost like the tach goes up a few hundred rpm's then it grabs and takes off. Is this oil worn out? I was going to use Amsoil 10w-40 because it is readily available for $5.99/qrt. Otherwise i can get Bel-Ray, Torco, or Maxum. What about the gold Honda bottle (syntheic)?