No Power,hm.need to comperession measure first if below 8bar it cant be power ,to fix this problem :cylinder head dismantle before this try to put several drops of motor oil to each cyl. and then measure compression if still weak that indicate worn walve seats and valves,if goes up it indicates worn piston rings and/or piston -cyl. clearance too high (needs overhaul). if indicates worn valwes just fix the worn valvws and valve seats ,guides,and ride again :) if not need overhaul ....