Dave, RS 250 are a rare and expensive bird these days...
To be fair, the plan is to ride on a small go kart track 15 minutes from home, where we used to go with Ohvale GP0 rental bikes.
Then due to the noise the GP0 were banned, so a few weeks ago we drove one hour and half to go to another kart track with GP0. But the guy who rents them (whom we know well) screwed us with the price, so now our plan is to sack the GP0 and buy a small bike that could ride in the small track close to home. With a regular 125 there shouldn't be noise problems... Hopefully.
The idea of having our own bike and a track so close is quite exciting. Hope it will work out!
