I just bought it about a month ago, so I tore it down to ensure the topend was healthy. Looks like the previous owner did a recent rebuild. I've only put an hour or so on the bike since I bought it. 93 octane fuel and Amsoil. I'm guessing the lack of build up is more so due to the very little time on the motor and not the fuel/oil. I was pretty happy when I saw the pistons, it's nice to buy a bike that doesn't need a new topend immediately for once :biggrin:
mods currently are
T5's
VF3s
Chariot timing plate at +5
K&N clamp ons
jetting is:
320 mains
Vitos needles for stock carbs, 4th clip
30 pilots
air temp 28F at 900 feet elevation.
I just sent the cylinders out to be ported, and I ordered a chariot cool head and a set of 19cc domes for race fuel, and 21cc's for pump gas. Should be fun when I get it back to go along with my '07 YFZ 450.