I didn't see the episode (we don't get cafe racer tv here in Canada), but did he claim this was a dyno'd 140 HP??
A lot of people like to BS about what kind of power their car/bike is making....
logic is typically as follows: "well, stock it made 67 HP, add the overbore pistons, and that should give me an extra 40...modified carbs sound like they'd be good for 10 - 15...velocity stacks should be good for an additional 5 over the airbox....and by cutting off the exhaust at about the oil pan, that should free up a lot! At least 20 HP!"
And there you have a magical 140 HP....
Now I'm not saying this is the case with this bike, because I honestly haven't seen it or know anything about it....but every guy out there with a 350 chevy and a chrome air cleaner lid is typically making in the 500 HP range too if you ask them...and 99.9% of the time, that car hasn't been within a mile of a dyno.