The 2007 SC125 I have here has a history of seizing up. Whilst looking at a cause for a oil tank leak I found even after removing the engine oil feed pipe, very little, hardly any, oil came out of the tank. I managed to do a straight pull on the pipe fitting underneath. Out poured all oil in the tank. I'll post pictures of what I found, there's a filter on the fitting but it was completely blocked up, just allowing enough to cause the leak. I think this fitting is pretty generic on a lot of these little bikes. Be warned!