I have just bought a Aprilia Rs125 its got a new battery etc it will start ok but after a few minutes or so of riding the power dies down and then stops, could this be the regulator

Tony Phelps, March 2010

alos these rs 125's are renowned for running weak and also seem to get water in the fuel tanks whcih also makes them run weak another of the problems they have is the tickover screw wears the throttle slide and then it will not lift the slide up enough to get it to idle but this will not make it cut out.they use the phb28 as standard on the non 33 bhp model whcih is a 28mm delorto carb.i hate these carbs thsy have nothing but design problems.you cant beat a good mikuni or keihin carb.

adam bike doctor, March 2010

could be many things,does it just cut out like you are turning off the ignition switch or is it gradual thing and does the rear wheel lock up for a second before it stops?will it start again afte a few minutes?have you tried to ride it with the fuel cap open?is there pleanty of 2 stroke oil in the tank?does the exhaust kick out blue smoke if you rev the engine?

adam bike doctor, March 2010

It sounds like a blocked breather on the fuel tank

hillrally, March 2010