Just got an Aprilia RX50 2006 (am6 engine), it has been sat for a while with the previous owner. It had a new piston, rings and cylinder head just before I got it.
However the speed is very slow and there seems to be problems in the gears .
I can pull away in first gear, but the revs go stupidly high. When I work through the other gears, after about half throttle it does nothing and provides no power. I couldn't even get to 25mph. It sort of 'splutters'.
I've been told this may be because it needs new crank seals, is this the case?
Any help appreciated, many thanks.