Hi! Today, 2100kms after the previews oil change, I decided to change the oil on my 2009 YZF R125. Previously I used Castrol 4T 10W-40 semi-synthetic oil, but now I chose to use Motorex top speed 4T 10W-40 "Synthetic performance" oil as they recommend for this bike on their website's oil finder. First I started the bike, no problem, after idling for about 1 minute I turned it off and waited 30min for the oil to fall back down. Then drained the old oil and removed the oil filter, everything was fine with the previous oil filter and oil, no metal shavings. So I installed a new oil filter and filled up the engine with the new oil. When I was done filling up the engine, I tried to start it, but it kept on cranking without starting. I insisted but nothing. Then I tried to start it on a downhill incline, I got the engine running but when back to idle it stalled. After some tries I got it running by, again trying to start it with the starter motor. It was more or less stable, I quickly loosened the oil pressure check screw to check if I had oil pressure at the valves. It took less than one minute to get oil seeping through the threads, according to the manual that's ok. After all that I went for a 20kms ride. Everything seemed ok, the clutch, gears, and acceleration was the same. (This kind of not starting but cranking problem already happened to me before! After some trying, I was always able to start it. But this never happened after an oil change!) Now I am wondering what the hell happened there??? Is it okay to keep riding it?