u mean a rg 125 f jp ?these are prone to the powervalves breaking in half and hitting the piston mate so be careful what you buy they are always low on compression if it has this problem ,i have had a few of these in the past and everyone had this problem the powervalves (2) have a shaft on them that goes up to a chamber at the top of the barel and an arm lifts them both up when the cables move which is connected to a servo(motor)but the shafts snap off from the main part of the powervalves,and they are in 3 pieces so they are expensive to buy.if you get stuck though i have got a good barrel that has had a steel liner fitted into it and the powervalves have been capped off .hope yours is ok though mate.t c adam :)
adam bike doctor
October 2006
howtomendit.com for free repair help, information and advice.
